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Hong HP, Thomovsky SA, Lewis MJ, Bentley RT, Shelton GD. Clinical characteristics of non-infectious inflammatory myopathy in the boxer dog. J Small Anim Pract 2021; 62:765-774. [PMID: 34002872 DOI: 10.1111/jsap.13350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Revised: 02/18/2021] [Accepted: 04/18/2021] [Indexed: 12/01/2022]
Abstract
OBJECTIVES To evaluate the clinical characteristics, treatment, outcome and potential association between non-infectious inflammatory myopathy and malignancy in boxer dogs. MATERIALS AND METHODS Boxer dogs histologically diagnosed with non-infectious inflammatory myopathy at the Comparative Neuromuscular Laboratory, University of California San Diego from 2010 to 2018 and with complete medical records were included in this retrospective study. Signalment, history, clinical signs, clinicopathologic findings, treatment and outcome were documented. RESULTS Twenty-eight boxer dogs with non-infectious inflammatory myopathy, aged 1 to 11 years, were included. Eighteen were male (16 neutered; two entire) and 10 were female (seven spayed; three entire). Clinical signs included generalised weakness (n=17), dysphagia (n=11) and weight loss (n=10). Serum creatine kinase activity was elevated in all 20 cases tested (range 908 to 138,000 IU/L). One dog had undifferentiated round cell neoplastic infiltration within the muscle at the time of inflammatory myopathy diagnosis. Five dogs historically had mast cell tumours and 21 dogs were not diagnosed with neoplasia prior, at the time of or after inflammatory myopathy diagnosis. Treatment included glucocorticoid monotherapy (n=12), cyclosporine monotherapy (n=1) or multiple immune-suppressive medications (n=14). Six dogs neurologically improved, 11 improved but relapsed while on treatment, seven did not improve. Eight dogs were euthanased, one died, four were lost to follow-up. CLINICAL SIGNIFICANCE Boxer dogs with non-infectious inflammatory myopathy can present for generalised weakness and dysphagia; long-term successful outcome is uncommon. The relationship between neoplasia and non-infectious inflammatory myopathy in boxer dogs remains unclear; future prospective studies evaluating a larger cohort are warranted.
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Affiliation(s)
- H P Hong
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - S A Thomovsky
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - M J Lewis
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - R T Bentley
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, 47907, USA
| | - G D Shelton
- Department of Pathology, School of Medicine, University of California at San Diego, La Jolla, CA, USA
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Minor KM, Letko A, Becker D, Drögemüller M, Mandigers PJJ, Bellekom SR, Leegwater PAJ, Stassen QEM, Putschbach K, Fischer A, Flegel T, Matiasek K, Ekenstedt KJ, Furrow E, Patterson EE, Platt SR, Kelly PA, Cassidy JP, Shelton GD, Lucot K, Bannasch DL, Martineau H, Muir CF, Priestnall SL, Henke D, Oevermann A, Jagannathan V, Mickelson JR, Drögemüller C. Canine NAPEPLD-associated models of human myelin disorders. Sci Rep 2018; 8:5818. [PMID: 29643404 PMCID: PMC5895582 DOI: 10.1038/s41598-018-23938-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 03/20/2018] [Indexed: 01/05/2023] Open
Abstract
Canine leukoencephalomyelopathy (LEMP) is a juvenile-onset neurodegenerative disorder of the CNS white matter currently described in Rottweiler and Leonberger dogs. Genome-wide association study (GWAS) allowed us to map LEMP in a Leonberger cohort to dog chromosome 18. Subsequent whole genome re-sequencing of a Leonberger case enabled the identification of a single private homozygous non-synonymous missense variant located in the highly conserved metallo-beta-lactamase domain of the N-acyl phosphatidylethanolamine phospholipase D (NAPEPLD) gene, encoding an enzyme of the endocannabinoid system. We then sequenced this gene in LEMP-affected Rottweilers and identified a different frameshift variant, which is predicted to replace the C-terminal metallo-beta-lactamase domain of the wild type protein. Haplotype analysis of SNP array genotypes revealed that the frameshift variant was present in diverse haplotypes in Rottweilers, and also in Great Danes, indicating an old origin of this second NAPEPLD variant. The identification of different NAPEPLD variants in dog breeds affected by leukoencephalopathies with heterogeneous pathological features, implicates the NAPEPLD enzyme as important in myelin homeostasis, and suggests a novel candidate gene for myelination disorders in people.
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Affiliation(s)
- K M Minor
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, MN, 55108, USA
| | - A Letko
- Institute of Genetics, University of Bern, Bern, 3001, Switzerland
| | - D Becker
- Institute of Genetics, University of Bern, Bern, 3001, Switzerland
| | - M Drögemüller
- Institute of Genetics, University of Bern, Bern, 3001, Switzerland
| | - P J J Mandigers
- Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, 3508, CM, The Netherlands
| | - S R Bellekom
- Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, 3508, CM, The Netherlands
| | - P A J Leegwater
- Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, 3508, CM, The Netherlands
| | - Q E M Stassen
- Department of Clinical Sciences of Companion Animals, Utrecht University, Utrecht, 3508, CM, The Netherlands
| | - K Putschbach
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Munich, 80539, Germany
| | - A Fischer
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Munich, 80539, Germany
| | - T Flegel
- Department of Small Animal Medicine, University of Leipzig, Leipzig, 04103, Germany
| | - K Matiasek
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Munich, 80539, Germany
| | - K J Ekenstedt
- Department of Basic Medical Sciences, Purdue University, West Lafayette, IN, 47907, USA
| | - E Furrow
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, MN, 55108, USA
| | - E E Patterson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, MN, 55108, USA
| | - S R Platt
- Small Animal Medicine and Surgery, University of Georgia, Athens, GA, 30602, USA
| | - P A Kelly
- Veterinary Sciences Centre, University College Dublin, Dublin, D04 V1W8, Ireland
| | - J P Cassidy
- Veterinary Sciences Centre, University College Dublin, Dublin, D04 V1W8, Ireland
| | - G D Shelton
- Department of Pathology, University of California, La Jolla, CA, 92093, USA
| | - K Lucot
- Department of Population Health and Reproduction, University of California-Davis, Davis, CA, 95616, USA
| | - D L Bannasch
- Department of Population Health and Reproduction, University of California-Davis, Davis, CA, 95616, USA
| | - H Martineau
- Pathobiology and Population Sciences, The Royal Veterinary College, North Mymms, AL9 7TA, UK
| | - C F Muir
- Pathobiology and Population Sciences, The Royal Veterinary College, North Mymms, AL9 7TA, UK
| | - S L Priestnall
- Pathobiology and Population Sciences, The Royal Veterinary College, North Mymms, AL9 7TA, UK
| | - D Henke
- Division of Clinical Neurology, University of Bern, Bern, 3001, Switzerland
| | - A Oevermann
- Division of Neurological Sciences, University of Bern, Bern, 3001, Switzerland
| | - V Jagannathan
- Institute of Genetics, University of Bern, Bern, 3001, Switzerland
| | - J R Mickelson
- Department of Veterinary and Biomedical Sciences, University of Minnesota, Saint Paul, MN, 55108, USA
| | - C Drögemüller
- Institute of Genetics, University of Bern, Bern, 3001, Switzerland.
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3
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Rossman PM, Thomovsky SA, Schafbuch RM, Guo LT, Shelton GD. Myositis, Ganglioneuritis, and Myocarditis with Distinct Perifascicular Muscle Atrophy in a 2-Year-Old Male Boxer. Front Vet Sci 2018. [PMID: 29516006 PMCID: PMC5826211 DOI: 10.3389/fvets.2018.00020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
A 2-year-old male, intact Boxer was referred for chronic diarrhea, hyporexia, labored breathing, weakness and elevated creatine kinase, and alanine aminotransferase activities. Initial examination and diagnostics revealed a peripheral nervous system neurolocalization, atrial premature complexes, and generalized megaesophagus. Progressive worsening of the dog's condition was noted after 36 h; the dog developed aspiration pneumonia, was febrile and oxygen dependent. The owners elected humane euthanasia. Immediately postmortem biopsies of the left cranial tibial and triceps muscles and the left peroneal nerve were obtained. Postmortem histology revealed concurrent myositis, myocarditis, endocarditis, and ganglioneuritis. Mixed mononuclear cell infiltrations and a distinct perifascicular pattern of muscle fiber atrophy was present in both muscles. This is a novel case of diffuse inflammatory myopathy with a distinct perifascicular pattern of atrophy in addition to endocarditis, myocarditis, and epicarditis.
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Affiliation(s)
- Paul M Rossman
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, United States
| | - Stephanie A Thomovsky
- Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN, United States
| | - Ryan M Schafbuch
- Indiana Animal Disease Diagnostic Laboratory, West Lafayette, IN, United States
| | - Ling T Guo
- Comparative Neuromuscular Laboratory, Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA, United States
| | - G D Shelton
- Comparative Neuromuscular Laboratory, Department of Pathology, School of Medicine, University of California, San Diego, La Jolla, CA, United States
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Jeandel A, Garosi LS, Davies L, Guo LT, Salgüero R, Shelton GD. Late-onset Becker-type muscular dystrophy in a Border terrier dog. J Small Anim Pract 2018; 60:514-517. [PMID: 29377139 DOI: 10.1111/jsap.12824] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 07/02/2017] [Accepted: 09/19/2017] [Indexed: 11/27/2022]
Abstract
A 9-year-old Border terrier was presented to a referral hospital after a 1-year history of progressive stiffness and exercise intolerance. Neurological examination was consistent with a neuromuscular disorder. Serum creatine kinase activity was mildly elevated. A myopathy was suspected based on MRI findings and electrophysiological examination. Muscle histopathology was consistent with a severe non-inflammatory myopathy of a dystrophic type. Immunofluorescence and western blotting confirmed a dystrophinopathy with an 80-kDa truncated dystrophin fragment similar to Becker muscular dystrophy in people. To our knowledge, this is the first description of a late-onset Becker-type muscular dystrophy in a dog, and the first description of a dystrophinopathy in a Border terrier. Muscular dystrophy in dogs should not be ruled out based on late onset clinical signs and only mildly elevated creatine kinase.
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Affiliation(s)
- A Jeandel
- Davies Veterinary Specialists, Hitchin, Hertfordshire SG5 3HR, UK
| | - L S Garosi
- Davies Veterinary Specialists, Hitchin, Hertfordshire SG5 3HR, UK
| | - L Davies
- Smart Veterinary Clinic, Swansea, Wales SA7 9LH, UK
| | - L T Guo
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, California 92093, USA
| | - R Salgüero
- Davies Veterinary Specialists, Hitchin, Hertfordshire SG5 3HR, UK
| | - G D Shelton
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, California 92093, USA
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5
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Strøm PC, Marks SL, Rivera JA, Shelton GD. Dysphagia secondary to focal inflammatory myopathy and consequent dorsiflexion of the tongue in a dog. J Small Anim Pract 2018; 59:714-718. [DOI: 10.1111/jsap.12819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 08/07/2017] [Accepted: 10/31/2017] [Indexed: 11/29/2022]
Affiliation(s)
- P. C. Strøm
- William R. Pritchard Veterinary Medical Teaching Hospital Davis California 95616 USA
| | - S. L. Marks
- Department of Medicine and Epidemiology, School of Veterinary Medicine University of California, Davis Davis California 95616 USA
| | - J. A. Rivera
- William R. Pritchard Veterinary Medical Teaching Hospital Davis California 95616 USA
| | - G. D. Shelton
- Department of Pathology, School of Medicine University of California San Diego La Jolla California 92307 USA
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6
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Packer RA, Logan MA, Guo LT, Apte SS, Bader H, O'Brien DP, Johnson G, Shelton GD. Clinical Phenotype of Musladin-Lueke Syndrome in 2 Beagles. J Vet Intern Med 2017; 31:532-538. [PMID: 28158899 PMCID: PMC5354057 DOI: 10.1111/jvim.14654] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 10/18/2016] [Accepted: 12/08/2016] [Indexed: 01/30/2023] Open
Abstract
Musladin‐Lueke syndrome (MLS), previously termed Chinese Beagle syndrome, is an autosomal‐recessive connective tissue disorder characterized by extensive fibrosis of the skin and joints that was first identified in Beagles in the 1970s. Recent research identified a founder mutation (c.660C>T; p.R221C) in the ADAMTSL2 gene in Beagles with MLS. Here, we report the detailed clinical phenotype and laboratory findings in 2 Beagles affected with MLS. We discuss these findings in relation to the human disorder geleophysic dysplasia (GD), which also arises from recessive ADAMTSL2 mutations, and recent findings in Adamtsl2‐deficient mice.
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Affiliation(s)
- R A Packer
- Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN.,Department of Basic Medical Sciences, Purdue University, West Lafayette, IN
| | - M A Logan
- Department of Veterinary Clinical Sciences, Purdue University, West Lafayette, IN.,Department of Basic Medical Sciences, Purdue University, West Lafayette, IN
| | - L T Guo
- Department of Pathology, School of Medicine, University of California - San Diego, La Jolla, CA
| | - S S Apte
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH
| | - H Bader
- Department of Biomedical Engineering, Cleveland Clinic Lerner Research Institute, Cleveland, OH
| | - D P O'Brien
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO
| | - G Johnson
- Department of Veterinary Medicine and Surgery, University of Missouri, Columbia, MO
| | - G D Shelton
- Department of Pathology, School of Medicine, University of California - San Diego, La Jolla, CA
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7
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Durward-Akhurst SA, Finno CJ, Barnes N, Shivers J, Guo LT, Shelton GD, Valberg SJ. Major Histocompatibility Complex I and II Expression and Lymphocytic Subtypes in Muscle of Horses with Immune-Mediated Myositis. J Vet Intern Med 2016; 30:1313-21. [PMID: 27352021 PMCID: PMC5094553 DOI: 10.1111/jvim.14371] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 03/25/2016] [Accepted: 06/11/2016] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Major histocompatibility complex (MHC) I and II expression is not normally detected on sarcolemma, but is detected with lymphocytic infiltrates in immune-mediated myositis (IMM) of humans and dogs and in dysferlin-deficient muscular dystrophy. HYPOTHESIS/OBJECTIVES To determine if sarcolemmal MHC is expressed in active IMM in horses, if MHC expression is associated with lymphocytic subtype, and if dysferlin is expressed in IMM. ANIMALS Twenty-one IMM horses of Quarter Horse-related breeds, 3 healthy and 6 disease controls (3 pasture myopathy, 3 amylase-resistant polysaccharide storage myopathy [PSSM]). METHODS Immunohistochemical staining for MHC I, II, and CD4+, CD8+, CD20+ lymphocytes was performed on archived muscle of IMM and control horses. Scores were given for MHC I, II, and lymphocytic subtypes. Immunofluorescent staining for dysferlin, dystrophin, and a-sarcoglycan was performed. RESULTS Sarcolemmal MHC I and II expression was detected in 17/21 and 15/21 of IMM horses, respectively, and in specific fibers of PSSM horses, but not healthy or pasture myopathy controls. The CD4+, CD8+, and CD20+ cells were present in 20/21 IMM muscles with CD4+ predominance in 10/21 and CD8+ predominance in 6/21 of IMM horses. Dysferlin, dystrophin, and a-sarcoglycan staining were similar in IMM and control muscles. CONCLUSIONS AND CLINICAL IMPORTANCE Deficiencies of dysferlin, dystrophin, and a-sarcoglycan are not associated with IMM. Sarcolemmal MHC I and II expression in a proportion of myofibers of IMM horses in conjunction with lymphocytic infiltration supports an immune-mediated etiology for IMM. The MHC expression also occured in specific myofibers in PSSM horses in the absence of lymphocytic infiltrates.
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Affiliation(s)
- S A Durward-Akhurst
- Department of Veterinary Population Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN
| | - C J Finno
- Department of Population Health and Reproduction, University of California-Davis, Davis, CA
| | - N Barnes
- Department of Veterinary Population Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN
| | - J Shivers
- Department of Veterinary Population Sciences, College of Veterinary Medicine, University of Minnesota, St. Paul, MN
| | - L T Guo
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - G D Shelton
- Department of Pathology, University of California, San Diego, La Jolla, CA
| | - S J Valberg
- Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI
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8
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Polle F, Andrews FM, Gillon T, Eades SC, McConnico RS, Strain GM, Valberg SJ, Guo LT, Shelton GD. Suspected congenital centronuclear myopathy in an Arabian-cross foal. J Vet Intern Med 2016; 28:1886-91. [PMID: 25410957 PMCID: PMC4895639 DOI: 10.1111/jvim.12438] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/22/2014] [Accepted: 07/23/2014] [Indexed: 11/30/2022] Open
Affiliation(s)
- F Polle
- Equine Health Studies Program, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA
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Mhlanga-Mutangadura T, Johnson GS, Ashwini A, Shelton GD, Wennogle SA, Johnson GC, Kuroki K, O'Brien DP. A Homozygous RAB3GAP1:c.743delC Mutation in Rottweilers with Neuronal Vacuolation and Spinocerebellar Degeneration. J Vet Intern Med 2016; 30:813-8. [PMID: 26968732 PMCID: PMC4913561 DOI: 10.1111/jvim.13921] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 12/28/2015] [Accepted: 02/11/2016] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND A variety of presumed hereditary, neurologic diseases have been reported in young Rottweilers. Overlapping ages of onset and clinical signs have made antemortem diagnosis difficult. One of these diseases, neuronal vacuolation and spinocerebellar degeneration (NVSD) shares clinical and histological features with polyneuropathy with ocular abnormalities and neuronal vacuolation (POANV), a recently described hereditary disease in Black Russian Terriers (BRTs). Dogs with POANV harbor mutations in RAB3GAP1 which codes for a protein involved in membrane trafficking. HYPOTHESIS Rottweilers with NVSD will be homozygous for the RAB3GAP1:c.743delC allele associated with POANV in BRTs. ANIMALS Eight Rottweilers with NVSD confirmed at necropsy, 128 Rottweilers without early onset neurologic signs, and 468 randomly selected dogs from 169 other breeds. METHODS Retrospective case-control study. Dogs were genotyped for the RAB3GAP1:c.743delC allele with an allelic discrimination assay. RESULTS All 8 NVSD-affected dogs were homozygous for the RAB3GAP1:c.743delC allele while the 128 NVSD-free Rottweilers were either homozygous for the reference allele (n = 105) or heterozygous (n = 23) and the 468 genotyped dogs from other breeds were all homozygous for the reference allele. CONCLUSIONS AND CLINICAL IMPORTANCE The RAB3GAP1:c.743delC mutation is associated with a similar phenotype in Rottweilers and BRTs. Identification of the mutation permits a DNA test that can aid in the diagnosis of NVSD and identify carriers of the trait so that breeders can avoid producing affected dogs. Disruption of membrane trafficking could explain the neuronal vacuolation seen in NVSD and other spongiform encephalopathies.
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Affiliation(s)
- T Mhlanga-Mutangadura
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - G S Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - A Ashwini
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - G D Shelton
- Department of Pathology, University of California San Diego, La Jolla, CA
| | - S A Wennogle
- Department of Clinical Sciences, Colorado State University, Fort Collins, CO
| | - G C Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - K Kuroki
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO
| | - D P O'Brien
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO
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Hague DW, Humphries HD, Mitchell MA, Shelton GD. Risk Factors and Outcomes in Cats with Acquired Myasthenia Gravis (2001-2012). J Vet Intern Med 2015; 29:1307-12. [PMID: 26308738 PMCID: PMC4858034 DOI: 10.1111/jvim.13596] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Revised: 05/26/2015] [Accepted: 07/21/2015] [Indexed: 11/30/2022] Open
Abstract
Background Acquired myasthenia gravis (MG) in cats most commonly causes generalized weakness without megaesophagus and is more often associated with a cranial mediastinal mass, compared to dogs. Hypothesis/Objectives To extend the clinical findings described in the report of 2000 on MG in cats (J Am Vet Med Assoc 215:55–57). Animals Two hundred and thirty‐five cats with MG. Methods Retrospective case study to evaluate the long‐term outcome and incidence of spontaneous remission in myasthenic cats. Information including signalment, clinical presentation, presence of and type of cranial mediastinal mass, treatment including surgical versus medical, survival time, and outcome including spontaneous remissions was collected and analyzed in cats diagnosed at the Comparative Neuromuscular Laboratory, University of California San Diego by detection of acetylcholine receptor antibody titers >0.3 nmol/L by immunoprecipitation radioimmunosassay. Results Acquired MG in cats is associated with a euthanasia rate of 58%. Abyssinian and Somali cats had an increased incidence of MG compared to mixed breed cats or cats of other breeds. A cranial mediastinal mass, most commonly thymoma, was observed in 52% of the cats, which is higher than in the previous report. Spontaneous remission is not a characteristic of MG in cats. Conclusions and clinical importance Myasthenia gravis in cats is a chronic disease associated with a high incidence of a cranial mediastinal mass. Spontaneous remission is not common and clinicians should warn owners of the necessity for long‐term treatment. The clinical outcome with a cranial mediastinal mass did not differ between surgical or medical treatment.
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Affiliation(s)
- D W Hague
- College of Veterinary Medicine, University of Illinois, Urbana, IL
| | - H D Humphries
- Department of Pathology, School of Medicine, University of California, San Diego, CA
| | - M A Mitchell
- College of Veterinary Medicine, University of Illinois, Urbana, IL
| | - G D Shelton
- Department of Pathology, School of Medicine, University of California, San Diego, CA
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11
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Giannasi C, Tappin SW, Guo LT, Shelton GD, Palus V. Dystrophin-deficient muscular dystrophy in two lurcher siblings. J Small Anim Pract 2015; 56:577-80. [PMID: 25622540 DOI: 10.1111/jsap.12331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 11/12/2014] [Accepted: 11/26/2014] [Indexed: 11/28/2022]
Abstract
Two cases of dystrophin-deficient muscular dystrophy in 16-week-old male lurcher siblings are reported. The myopathies were characterised by regurgitation, progressive weakness and muscle wastage. The dogs had generalised weakness in all four limbs, with more pronounced weakness in the pelvic limbs. Reduced withdrawal in all limbs, muscle contracture and lingual hypertrophy were noted. Serum creatine kinase activities were markedly elevated. Electromyographic abnormalities included fibrillation potentials. Histopathological and immunohistochemical staining were consistent with dystrophin-deficient muscular dystrophy. Clinical improvement was noted in one of the cases with L-carnitine supplementation and supportive therapy. Genetic transmission of the disease was postulated as the dogs were siblings.
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Affiliation(s)
| | - S W Tappin
- Dick White Referrals, Station Farm, London Road, Six Mile Bottom, Cambridgeshire, CB8 0UH
| | - L T Guo
- Department of Pathology, University of California San Diego, La Jolla, CA, 92093, USA
| | - G D Shelton
- Department of Pathology, University of California San Diego, La Jolla, CA, 92093, USA
| | - V Palus
- Dick White Referrals, Station Farm, London Road, Six Mile Bottom, Cambridgeshire, CB8 0UH
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12
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Snead ECR, Taylor SM, van der Kooij M, Cosford K, Beggs AH, Shelton GD. Clinical phenotype of X-linked myotubular myopathy in Labrador Retriever puppies. J Vet Intern Med 2015; 29:254-60. [PMID: 25581576 PMCID: PMC4308540 DOI: 10.1111/jvim.12513] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Revised: 10/22/2014] [Accepted: 10/29/2014] [Indexed: 01/19/2023] Open
Abstract
Background Seven male Labrador Retriever puppies from 3 different litters, born to clinically normal dams and sires, were evaluated for progressive weakness and muscle atrophy. Muscle biopsies identified a congenital myopathy with pathologic features consistent with myotubular myopathy. Further investigations identified a pathogenic mutation in the myotubularin gene, confirming that these puppies had X‐linked myotubular myopathy (XLMTM). Objective To review the clinical phenotype, electrodiagnostic and laboratory features of XLMTM in this cohort of Labrador Retrievers. Results Male puppies with XLMTM were small and thin compared with their normal littermates. Generalized weakness and muscle atrophy were present by 7 weeks of age in some puppies and evident to most owners by 14 weeks of age. Affected puppies stood with an arched spine and low head carriage, and walked with a short, choppy stride. Muscle atrophy was severe and progressive. Patellar reflexes were absent. Laryngeal and esophageal dysfunction, and weakness of the masticatory muscles occurred in puppies surviving beyond 4 months of age. Serum creatine kinase activity was normal or only mildly increased. EMG findings were nonspecific and included positive sharp waves and fibrillation potentials. Clinical signs progressed rapidly, with most affected puppies unable to walk within 3–4 weeks after clinical signs were first noticed. Conclusions and Clinical Importance Although initial clinical signs of XLMTM are similar to the phenotypically milder centronuclear myopathy in Labrador Retrievers, XLMTM is a rapidly progressive and fatal myopathy. Clinicians should be aware of these 2 distinct myopathies with similar clinical presentations in the Labrador retriever breed.
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Affiliation(s)
- E C R Snead
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK, Canada
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13
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Munday JS, Shelton GD, Willox S, Kingsbury DD. Muscular dystrophy due to a sarcoglycan deficiency in a female Dobermann dog. J Small Anim Pract 2014; 56:414-6. [PMID: 25482856 DOI: 10.1111/jsap.12306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Revised: 09/25/2014] [Accepted: 09/30/2014] [Indexed: 11/27/2022]
Abstract
A four-month-old female Dobermann presented with myalgia, dysphagia, progressive weakness and loss of body condition. Diagnostic evaluation at nine months of age revealed markedly elevated serum creatine kinase activity, electromyographic abnormalities and histological evidence of chronic-active muscle necrosis. Imaging confirmed dysphagia and aspiration pneumonia. Muscular dystrophy was suspected and immunohistochemical staining of muscle cryosections demonstrated reduced sarcoglycans. Treatment consisted of gastrostomy, and over the next 5 months the dog gained weight, despite continued loss of muscle mass. The dog died at 14 months of age after developing clinical signs of aspiration pneumonia. To the authors' knowledge, this is the first report of muscular dystrophy in a Dobermann and only the second detailed report of a canine sarcoglycanopathy. Supportive care resulted in an acceptable quality of life for 10 months after clinical signs were first observed.
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Affiliation(s)
- J S Munday
- Institute of Veterinary, Animal, and Biomedical Sciences, Massey University, Palmerston North, New Zealand
| | - G D Shelton
- Institute of Veterinary, Animal, and Biomedical Sciences, Massey University, Palmerston North, New Zealand.,Department of Pathology, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - S Willox
- Institute of Veterinary, Animal, and Biomedical Sciences, Massey University, Palmerston North, New Zealand.,Murray's Veterinary Clinic, Mosgiel, New Zealand
| | - D D Kingsbury
- Institute of Veterinary, Animal, and Biomedical Sciences, Massey University, Palmerston North, New Zealand.,Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, CA, 95616, USA
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14
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Beltran E, Shelton GD, Guo LT, Dennis R, Sanchez-Masian D, Robinson D, De Risio L. Dystrophin-deficient muscular dystrophy in a Norfolk terrier. J Small Anim Pract 2014; 56:351-4. [PMID: 25353637 DOI: 10.1111/jsap.12292] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/07/2014] [Accepted: 08/29/2014] [Indexed: 11/29/2022]
Abstract
A six-month-old male entire Norfolk terrier was presented with a 3-month history of poor development, reluctance to exercise and progressive and diffuse muscle atrophy. Serum creatine kinase concentration was markedly elevated. Magnetic resonance imaging of the epaxial muscles revealed asymmetrical streaky signal changes aligned within the muscle fibres (hyperintense on T2-weighted images and short-tau inversion recovery with moderate contrast enhancement on T1-weighted images). Electromyography revealed pseudomyotonic discharges and fibrillation potentials localised at the level of the supraspinatus, epaxial muscles and tibial cranialis muscles. Muscle biopsy results were consistent with dystrophin-deficient muscular dystrophy. The dog remained stable 7 months after diagnosis with coenzyme Q10 and l-carnitine; however after that time, there was a marked deterioration and the owners elected euthanasia. This case report describes the clinical presentation, magnetic resonance imaging, electrodiagnostic and histopathological findings with immunohistochemical analysis in a Norfolk terrier with confirmed dystrophin-deficient muscular dystrophy, which has not been previously described in this breed.
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Affiliation(s)
- E Beltran
- Centre for Small Animal Studies, Animal Health Trust, Newmarket, Suffolk, CB87UU
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15
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Aleman M, Dickinson PJ, Williams DC, Sturges BK, LeCouteur RA, Vernau KM, Shelton GD. Electrophysiologic confirmation of heterogenous motor polyneuropathy in young cats. J Vet Intern Med 2014; 28:1789-98. [PMID: 25231268 PMCID: PMC4895637 DOI: 10.1111/jvim.12439] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2014] [Revised: 05/06/2014] [Accepted: 07/23/2014] [Indexed: 12/11/2022] Open
Abstract
Background Reports of motor polyneuropathies in young cats are scarce. Further, in‐depth electrophysiologic evaluation to confirm a motor polyneuropathy in young cats of various breeds other than 2 Bengal cats is lacking. Hypothesis/Objectives To confirm a motor polyneuropathy in young cats of various breeds. Animals Five young cats with heterogenous chronic or relapsing episodes of weakness. Methods Retrospective case series. Cats were presented for evaluation of generalized neuromuscular disease and underwent electrophysiologic examination including electromyography, nerve conduction, and repetitive nerve stimulation. Minimum database and muscle and nerve biopsy analyses were carried out. Descriptive statistics were performed. Results Disease onset was at 3 months to 1 year of age and in 5 breeds. The most common clinical sign (5 of 5 cats) was weakness. Additional neurologic deficits consisted of palmigrade and plantigrade posture (4/4), low carriage of the head and tail (4/4), and variable segmental reflex deficits (5/5). Motor nerve conduction studies were abnormal for the ulnar (4/4), peroneal (5/5), and tibial (2/2) nerves (increased latencies, reduced amplitudes, slow velocities). A marked decrement was observed on repetitive nerve stimulation of the peroneal nerve in 3 cats for which autoimmune myasthenia gravis was ruled out. All sensory nerve conduction studies were normal. Histologic evaluation of muscle and nerve biopsies supported heterogenous alterations consistent with motor polyneuropathy with distal nerve fiber loss. Conclusions and Clinical Importance Heterogenous motor polyneuropathies should be considered in young cats of any breed and sex that are presented with relapsing or progressive generalized neuromuscular disease.
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Affiliation(s)
- M Aleman
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA
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16
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Needle DB, Hollinger C, Shelton GD, Fitzgerald SD. Necrotizing and eosinophilic masticatory myositis in farmed mink: a preliminary description. J Comp Pathol 2014; 151:217-27. [PMID: 25016423 DOI: 10.1016/j.jcpa.2014.04.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 03/18/2014] [Accepted: 04/29/2014] [Indexed: 10/25/2022]
Abstract
This report describes necrotizing and eosinophilic myositis affecting the masticatory muscles of a group of mink. Affected animals demonstrated sudden death with marked subcutaneous oedema over the dorsal head. The temporalis and masseter muscles were pale, swollen and friable. Histologic changes consisted of varying degrees of myodegeneration, myonecrosis and inflammation. Eosinophils were prominent in the inflammatory infiltrate. Similar to dogs, masticatory muscles in mink were found to contain unique type 2M fibres, suggesting a possible target for an immune response. Aerobic and anaerobic tissue cultures of the affected musculature revealed no significant pathogens. Histological and nutritional analyses were not typical of vitamin E/selenium deficiency. This case series supports the existence of a novel disease entity in mink with some features comparable with masticatory muscle myositis in dogs.
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Affiliation(s)
- D B Needle
- Department of Pathobiology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48894, USA
| | - C Hollinger
- Department of Pathobiology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48894, USA
| | - G D Shelton
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093-0709, USA
| | - S D Fitzgerald
- Department of Pathobiology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48894, USA.
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17
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Mace S, Shelton GD, Eddlestone S. [Megaesophagus in the dog and cat]. Tierarztl Prax Ausg K Kleintiere Heimtiere 2013; 41:123-132. [PMID: 23608968] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Accepted: 02/27/2013] [Indexed: 06/02/2023]
Abstract
Megaesophagus is a disorder of the esophagus characterized by diffuse dilation and decreased peristalsis. It is classified into congenital and acquired forms. Gastrointestinal, endocrine, immune-mediated, neuromuscular, paraneoplastic, and toxic disorders have been associated with acquired megaesophagus. Common clinical signs of megaesophagus are regurgitation, weight loss, coughing, and halitosis. Most cases of megaesophagus can be diagnosed using thoracic radiography; however, diagnosing the underlying cause requires a thorough history and additional diagnostics. The treatment, management, and prognosis of megaesophagus vary greatly depending on the underlying cause.
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Affiliation(s)
- S Mace
- Veterinary Specialty Center of the Hudson Valley, NY, USA
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18
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Affiliation(s)
- S. Eminaga
- Dick White Referrals; Station Farm, London Road, Six Mile Bottom; Cambridgeshire; CB8 0UH
| | - G. B. Cherubini
- Dick White Referrals; Station Farm, London Road, Six Mile Bottom; Cambridgeshire; CB8 0UH
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Farias FHG, Zeng R, Johnson GS, Shelton GD, Paquette D, O'Brien DP. A L2HGDH initiator methionine codon mutation in a Yorkshire terrier with L-2-hydroxyglutaric aciduria. BMC Vet Res 2012; 8:124. [PMID: 22834903 PMCID: PMC3461439 DOI: 10.1186/1746-6148-8-124] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 07/04/2012] [Indexed: 11/10/2022] Open
Abstract
Background L-2-hydroxyglutaric aciduria is a metabolic repair deficiency characterized by elevated levels of L-2-hydroxyglutaric acid in urine, blood and cerebrospinal fluid. Neurological signs associated with the disease in humans and dogs include seizures, ataxia and dementia. Case presentation Here we describe an 8 month old Yorkshire terrier that presented with episodes of hyperactivity and aggressive behavior. Between episodes, the dog’s behavior and neurologic examinations were normal. A T2 weighted MRI of the brain showed diffuse grey matter hyperintensity and a urine metabolite screen showed elevated 2-hydroxyglutaric acid. We sequenced all 10 exons and intron-exon borders of L2HGDH from the affected dog and identified a homozygous A to G transition in the initiator methionine codon. The first inframe methionine is at p.M183 which is past the mitochondrial targeting domain of the protein. Initiation of translation at p.M183 would encode an N-terminal truncated protein unlikely to be functional. Conclusions We have identified a mutation in the initiation codon of L2HGDH that is likely to result in a non-functional gene. The Yorkshire terrier could serve as an animal model to understand the pathogenesis of L-2-hydroxyglutaric aciduria and to evaluate potential therapies.
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Affiliation(s)
- Fabiana H G Farias
- Department of Veterinary Pathobiology, University of Missouri, Columbia, USA.
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20
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Rodenas S, Guo LT, Shelton GD. Myopathy associated with congenital fibre type disproportion in a young dog. J Comp Pathol 2012; 147:486-90. [PMID: 22789857 DOI: 10.1016/j.jcpa.2012.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Revised: 04/15/2012] [Accepted: 05/03/2012] [Indexed: 11/17/2022]
Abstract
A 4-month-old, female collie-cross dog was presented for evaluation of slowly progressive weakness, exercise intolerance and muscle atrophy. Neurological examination and electrodiagnostic testing were consistent with a generalized myopathy or, less likely, an axonal polyneuropathy. Muscle biopsy samples revealed marked variability in myofibre size with scattered or clustered atrophic or hypotrophic type 1 fibres. Type 1 fibres were 65% smaller than type 2A fibres and the percentage of type 1 fibres exceeded reference values for both limb muscles examined. On the basis of the clinical evaluation, pathological changes and the absence of another defined congenital or acquired myopathy, a diagnosis of a myopathy associated with congenital fibre type disproportion was made. Three months later the animal was humanely euthanized because of worsening clinical signs.
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Affiliation(s)
- S Rodenas
- Southern Counties Veterinary Specialists, Ringwood, Hampshire BH24 3JW, UK.
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21
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Abstract
Hypertrophic muscular dystrophy was diagnosed in a 10-month-old male Rat Terrier with hypersalivation, dysphagia, gait abnormalities, and generalized weakness. Serum creatine kinase activity was high, and electromyography revealed myotonic discharges. Histologic examination of a muscle biopsy specimen revealed muscle fiber degeneration, clusters of basophilic regenerating fibers, and endomysial fibrosis. Staining for dystrophin, a sarcolemmal protein, was decreased, compared with that in muscle specimens from clinically normal dogs. Treatment with mexiletene hydrochloride and procainamide hydrochloride resulted in temporary improvement in clinical signs, but the disease became refractory to treatment, and the dog was euthanatized. Clinical and histologic characteristics of this dystrophin deficiency-related muscular dystrophy were similar to those of X-linked muscular dystrophy in dogs, hypertrophic muscular dystrophy in cats, and Duchenne muscular dystrophy in humans.
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Affiliation(s)
- C A Wetterman
- Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USA
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22
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Sponseller BT, Valberg SJ, Schultz NE, Bedford H, Wong DM, Kersh K, Shelton GD. Equine multiple acyl-CoA dehydrogenase deficiency (MADD) associated with seasonal pasture myopathy in the midwestern United States. J Vet Intern Med 2012; 26:1012-8. [PMID: 22708588 DOI: 10.1111/j.1939-1676.2012.00957.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 02/16/2012] [Accepted: 05/09/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Seasonal pasture myopathy (SPM) is a highly fatal form of nonexertional rhabdomyolysis that occurs in pastured horses in the United States during autumn or spring. In Europe, a similar condition, atypical myopathy (AM), is common. Recently, a defect of lipid metabolism, multiple acyl-CoA dehydrogenase deficiency (MADD), has been identified in horses with AM. OBJECTIVE To determine if SPM in the United States is caused by MADD. ANIMALS Six horses diagnosed with SPM based on history, clinical signs, and serum creatine kinase activity, or postmortem findings. METHODS Retrospective descriptive study. Submissions to the Neuromuscular Diagnostic Laboratory at the University of Minnesota were reviewed between April 2009 and January 2010 to identify cases of SPM. Inclusion criteria were pastured, presenting with acute nonexertional rhabdomyolysis, and serum, urine, or muscle samples available for analysis. Horses were evaluated for MADD by urine organic acids, serum acylcarnitines, muscle carnitine, or histopathology. RESULTS Six horses had clinical signs and, where performed (4/6 horses), postmortem findings consistent with SPM. Affected muscle (4/4) showed degeneration with intramyofiber lipid accumulation, decreased free carnitine concentration, and increased carnitine esters. Serum acylcarnitine profiles (3/3) showed increases in short- and medium-chain acylcarnitines and urinary organic acid profiles (3/3) revealed increased ethylmalonic and methylsuccinic acid levels, and glycine conjugates, consistent with equine MADD. CONCLUSIONS AND CLINICAL IMPORTANCE Similar to AM, the biochemical defect causing SPM is MADD, which causes defective muscular lipid metabolism and excessive myofiber lipid content. Diagnosis can be made by assessing serum acylcarnitine and urine organic acid profiles.
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Affiliation(s)
- B T Sponseller
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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Nakamura RK, Russell NJ, Shelton GD. Adult-onset nemaline myopathy in a dog presenting with persistent atrial standstill and primary hypothyroidism. J Small Anim Pract 2012; 53:357-60. [DOI: 10.1111/j.1748-5827.2012.01221.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Foy DS, Trepanier LA, Shelton GD. Cholinergic crisis after neostigmine administration in a dog with acquired focal myasthenia gravis. J Vet Emerg Crit Care (San Antonio) 2012; 21:547-51. [PMID: 22316202 DOI: 10.1111/j.1476-4431.2011.00672.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2010] [Accepted: 07/14/2011] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To describe the presentation and successful management of a dog experiencing a cholinergic crisis after neostigmine administration. CASE SUMMARY An 18-month-old neutered male Maltese-crossbred dog was diagnosed with acquired focal myasthenia gravis based on history and clinical signs of dysphagia and regurgitation, multiple series of thoracic radiographs showing focal to generalized megaesophagus, and an increased acetylcholine receptor antibody titer. After this diagnosis, the dog was initially treated with a single oral dose of pyridostigmine and later injectable neostigmine due to difficulty swallowing. Within 15 minutes of receiving a single dose (0.05 mg/kg) of subcutaneous neostigmine, the dog began showing muscarinic cholinergic signs of salivation and defecation, which progressed to nicotinic cholinergic signs of weakness and tachypnea. Within 30 minutes the dog experienced respiratory arrest and required ventilation. After 16 hours of ventilation, the dog recovered uneventfully and subsequently achieved a clinical and serologic remission from myasthenia gravis without further treatment. NEW OR UNIQUE INFORMATION PROVIDED Cholinergic crisis and differentiation from a myasthenic crisis is described in the human literature. This case represents the first report in the veterinary literature of a cholinergic crisis in a dog treated with neostigmine.
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Affiliation(s)
- Daniel S Foy
- Department of Medical Sciences, University of Wisconsin-Madison, 2015 Linden Dr, Madison, WI 53706, USA.
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25
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Sykes JE, Dubey JP, Lindsay LL, Prato P, Lappin MR, Guo LT, Mizisin AP, Shelton GD. Severe myositis associated with Sarcocystis spp. infection in 2 dogs. J Vet Intern Med 2011; 25:1277-83. [PMID: 22092617 DOI: 10.1111/j.1939-1676.2011.00828.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Revised: 09/02/2011] [Accepted: 09/21/2011] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND Dogs are definitive hosts for numerous species of the intracellular protozoan parasite Sarcocystis. Reports of sarcocysts in muscles of dogs most often represent incidental findings. HYPOTHESIS/OBJECTIVES To report the clinicopathologic, ultrastructural, and molecular findings in 2 dogs with myositis associated with Sarcocystis spp. infection, as well as the response to treatment with antiprotozoal drugs. ANIMALS Two dogs with severe myositis in association with massive sarcocystosis. METHODS Retrospective case review. Affected dogs were identified by a diagnostic laboratory. Attending clinicians were contacted, and the medical records reviewed. Immunostaining and electron microscopy were performed on muscle biopsies. Biopsies also were subjected to 18S rRNA gene PCR. RESULTS Both dogs had fever, lymphopenia, thrombocytopenia, and increased serum alanine aminotransferase (ALT) activity when first evaluated. One dog developed hyperbilirubinemia. Subsequently, both dogs had increased serum creatine kinase activity and clinical signs of myositis, with reluctance to move, generalized pain, and muscle wasting. Histopathology of muscle biopsies showed severe inflammatory and necrotizing myopathy with numerous sarcocysts. Ultrastructural studies and 18S rRNA gene sequence results were consistent with infection with a Sarcocystis spp. other than Sarcocystis neurona. Both dogs initially were treated unsuccessfully with clindamycin and anti-inflammatory drugs. One dog died. The other dog subsequently responded to treatment with decoquinate. CONCLUSIONS AND CLINICAL IMPORTANCE Sarcocystis spp. infection should be included in the differential diagnosis for dogs that develop fever, thrombocytopenia, increased liver enzyme activities, and clinical and biochemical evidence of myositis. Although additional studies are required, decoquinate holds promise as an effective treatment for the disease.
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Affiliation(s)
- J E Sykes
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
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26
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Vanhaesebrouck AE, Shelton GD, Garosi L, Harcourt-Brown TR, Couturier J, Behr S, Harvey RJ, Jeffery ND, Matiasek K, Blakemore WF, Granger N. A novel movement disorder in related male Labrador Retrievers characterized by extreme generalized muscular stiffness. J Vet Intern Med 2011; 25:1089-96. [PMID: 21781161 DOI: 10.1111/j.1939-1676.2011.0757.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVES To describe the clinical phenotype of a new motor disorder in Labrador Retrievers. ANIMALS AND METHODS Case series study. Seven young male Labrador Retrievers presented for evaluation of stiff gait. RESULTS All affected dogs had generalized muscular stiffness, persistent at rest and resulting in restricted joint movements. They showed a forward flexed posture, festinating gait, and bradykinesia. Signs developed between 2 and 16 months of age and tended to stabilize in adulthood. Needle electromyogram in the conscious state showed continuous motor unit activity in resting epaxial and proximal limb muscles. This activity was abolished by general anesthesia. Muscle and nerve histopathology was normal. In 2 dogs necropsied, astrocytosis was evident throughout the spinal cord gray matter, reticular formation and caudate nuclei. Decreased neuronal counts were selectively found in the spinal cord Rexed's lamina VII, but not in VIII and IX. Pedigree analysis showed that the affected dogs were from 5 related litters. CONCLUSIONS AND CLINICAL IMPORTANCE This new hypertonicity syndrome in Labrador Retrievers is unique because of the selective distribution of the histological lesions, the lack of progression in adulthood, and its exclusive occurrence in male dogs. Pedigree analysis suggests an X-linked hereditary disease, although other modes of inheritance cannot be ruled out with certainty. We hypothesize that altered output from basal nuclei and reticular formation together with motor neuron disinhibition caused by a decreased number of spinal cord interneurons leads to the muscular stiffness.
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Affiliation(s)
- A E Vanhaesebrouck
- Department of Veterinary Medicine, The Queen's Veterinary School Hospital, University of Cambridge, Cambridge, UK.
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27
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Khorzad R, Whelan M, Sisson A, Shelton GD. Myasthenia gravis in dogs with an emphasis on treatment and critical care management. J Vet Emerg Crit Care (San Antonio) 2011; 21:193-208. [PMID: 21631705 DOI: 10.1111/j.1476-4431.2011.00636.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
OBJECTIVE To review the human and veterinary literature on the pathophysiology of myasthenia gravis (MG) and describe treatment options for clinical use in people and animals. DATA SOURCES Human and veterinary clinical reports, studies and reviews, textbooks, and recent research findings in MG from 1996 present, with a focus on treatment and patient management. HUMAN DATA SYNTHESIS MG is a well-described condition in people with new research and treatment options available. Many of the newest therapeutic options available in veterinary medicine for MG are based on current strategies used in people with this condition. Seronegative MG is well described in people and provides insight to clinical cases encountered in veterinary medicine when the index of suspicion is high though serologic tests are negative. VETERINARY DATA SYNTHESIS Previous studies in veterinary medicine focused on the use of acetylcholinesterase inhibitors as the main form of treatment in canine MG. Recent studies, mainly case series and case reports, emphasize the use of immunomodulatory treatments as an alternative for long-term treatment. However, there are no randomized, controlled studies on treatment with immunomodulatory therapy for MG in dogs available to assess the efficacy of this treatment strategy. CONCLUSIONS Although early recognition of clinical signs is most important in the outcome of patients with MG, further understanding the pathophysiology of MG may lead to earlier diagnosis and novel treatment strategies. The discovery of additional autoantibodies against striated muscle proteins in dogs, should enhance our understanding of diseases affecting the neuromuscular junction. In addition, clinical data for canine MG could be applied to other autoimmune disorders.
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Affiliation(s)
- Roxanna Khorzad
- Department of Emergency and Critical Care, Angell Animal Medical Center, Boston, MA 02130, USA
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28
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Haley AC, Platt SR, Kent M, Schatzberg SJ, Durham A, Cochrane S, Westworth D, Shelton GD. Breed-specific polymyositis in Hungarian Vizsla dogs. J Vet Intern Med 2011; 25:393-7. [PMID: 21281345 DOI: 10.1111/j.1939-1676.2010.0660.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Affiliation(s)
- A C Haley
- College of Veterinary Medicine, Department of Small Animal Medicine and Surgery, University of Georgia, Athens, GA, USA.
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Geiger DA, Miller AD, Cutter-Schatzberg K, Shelton GD, de Lahunta A, Schatzberg SJ. Encephalomyelopathy and polyneuropathy associated with neuronal vacuolation in two Boxer littermates. Vet Pathol 2009; 46:1160-5. [PMID: 19605909 DOI: 10.1354/vp.09-vp-0010-s-fl] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Neuronal vacuolation and spinocerebellar degeneration is a rare, presumably inherited condition that is reported only in Rottweilers and in crossbred dogs with known or potential Rottweiler heritage. Gross and histopathologic findings include laryngeal muscle atrophy, neuronal vacuolation, and a combined central and peripheral axonopathy. Two 6-month-old Boxer puppies from the same litter were referred for evaluation of progressive pelvic limb paresis and ataxia, upper airway stridor, and visual deficits. Examination of each dog suggested a combined myelopathy and peripheral neuropathy, as well as congenital ocular disease. Gross lesions were limited to atrophy of the intrinsic laryngeal muscles. Histopathologically, there was diffuse loss of axons and myelin in the dorsolateral and ventral funiculi throughout the spinal cord and extending into the caudal aspect of the brain stem. Vacuolation of scattered neuronal cell bodies was present in the spinal cord and selected brain stem nuclei. Multifocal axonal degeneration and demyelination was observed in the recurrent laryngeal nerve, sciatic nerve, and brachial plexus and was most severe in the recurrent laryngeal nerve. Ocular abnormalities included microphthalmia, cataracts, and retinal dysplasia. The findings in these Boxer dogs, unrelated to the Rottweiler breed, are analogous to the syndrome of neuronal vacuolation and spinocerebellar degeneration reported in Rottweilers.
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Affiliation(s)
- D A Geiger
- Bay Area Veterinary Specialists, San Leandro, CA, USA
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Salvadori C, Vattemi G, Lombardo R, Marini M, Cantile C, Shelton GD. Muscular dystrophy with reduced beta-sarcoglycan in a cat. J Comp Pathol 2009; 140:278-82. [PMID: 19203767 DOI: 10.1016/j.jcpa.2008.12.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 11/26/2008] [Accepted: 12/10/2008] [Indexed: 11/30/2022]
Abstract
A partial beta-sarcoglycan (SG) deficiency with retention of other components of the SG complex (SGC) is described in 6-month-old, intact male domestic shorthaired kitten that was referred for evaluation of weakness, reluctance to move and dyspnoea. Neurological deficits were restricted to the neuromuscular system. Muscle biopsy revealed moderate variability in myofibre size, with numerous atrophic rounded fibres, rare myofibre necrosis, regeneration and moderate perimysial and endomysial fibrosis. Immunohistochemistry revealed decreased expression of beta- and gamma-SG and western blotting revealed markedly decreased beta-SG with normal expression of alpha-, gamma- and delta-SG, caveolin-3 and calpain-3. Sarcoglycanopathy has not previously been described in cats. In human and canine sarcoglycanopathies the deficiency in any one of the SGs leads to secondary deficiency of the entire SGC. Such spontaneously arising muscular disease in animals can provide valuable models for equivalent human disorders.
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Affiliation(s)
- C Salvadori
- Department of Animal Pathology, University of Pisa, Viale delle Piagge 2, Pisa
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Affiliation(s)
- K Deitz
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
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Abstract
It is likely that most neuromuscular diseases that are described in humans will have a counterpart in our companion animals. With the advent of molecular genetics and the completion of the canine and feline genomes, an ever expanding number of DNA-based tests should become available for the diagnosis of muscle and peripheral nerve diseases. Molecular testing procedures should enable us to continue to unravel the molecular basis of neuromuscular diseases for which the cause is still unknown. It is important that accurate clinical evaluations and diagnostic testing, including muscle and peripheral nerve biopsies, are performed in order to reach these goals. This review focuses on recently identified inherited neuromuscular diseases in companion animals.
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Affiliation(s)
- G D Shelton
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093-0709, USA.
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Abstract
A 2-year-old, male Weimaraner with muscular dystrophy was presented with generalized muscle atrophy of the limbs; hypertrophy of the neck, infraspinatus, and lingual muscles; dysphagia; and regurgitation. Unilateral cryptorchidism, unilateral renal agenesis, and hiatal hernia were also detected. Spontaneous muscle activity was identified on myography. Serum creatine kinase was markedly elevated. Immunohistochemical staining for dystrophin was restricted to suspected revertant (characteristics of immaturity) fibers. Histologically, skeletal myofiber degeneration, endomysial fibrosis, and mineralization were present. Following euthanasia, necropsy revealed hypertrophy of the diaphragm and cardiac muscle fibrosis. This case of muscular dystrophy represents a slowly progressive form with organ agenesis.
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Affiliation(s)
- Wendy Irene Baltzer
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, Oregon 97331, USA
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36
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Pettigrew R, Fyfe JC, Gregory BL, Lipsitz D, Delahunta A, Summers BA, Shelton GD. CNS hypomyelination in Rat Terrier dogs with congenital goiter and a mutation in the thyroid peroxidase gene. Vet Pathol 2007; 44:50-6. [PMID: 17197623 DOI: 10.1354/vp.44-1-50] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Arrested physical development and neurologic abnormalities were identified in 3 of 5 Rat Terrier puppies at 9 weeks of age. Bilaterally firm symmetrical masses were palpated in the region of the thyroid glands. Low serum total (T4) and free thyroxine (FT4, by equilibrium dialysis) and markedly elevated thyroid stimulating hormone (TSH) concentrations supported the diagnosis of hypothyroidism. At necropsy, the thyroid gland was grossly enlarged and histologically exhibited severe, diffuse hyperplasia of the follicular epithelium. Gross examination of the central nervous system revealed a myelin deficiency, most evident in the corpus callosum. Regional distribution of hypomyelination was confirmed histologically, affecting the corpus callosum and, to a lesser degree, the corona radiata, the longitudinal fibers of the pons, the pyramids, and the lateral funiculi of the spinal cord. Myelin reduction was paralleled by axon reduction, suggesting that hypomyelination was a consequence of reduced axonal formation. A homozygous nonsense mutation in the thyroid peroxidase gene was identified in the affected puppies. The dam and a clinically normal litter mate were heterozygous for this mutation, confirming simple autosomal recessive inheritance of the disease trait. The same mutation, causing congenital hypothyroidism with a goiter was previously described in the Toy Fox Terrier breed. Given the ongoing practice of introducing the Toy Fox Terrier genetic background into some Rat Terrier breeding programs to obtain a smaller stature and the apparent relative incidence of the disorder in the 2 breeds, it is likely that this mutation crossed into the Rat Terrier breed from Toy Fox Terriers fairly recently.
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Affiliation(s)
- R Pettigrew
- Department of Pathology, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0709, USA
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37
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Aleman M, Watson JL, Williams DC, LeCouteur RA, Nieto JE, Shelton GD. Myopathy in horses with pituitary pars intermedia dysfunction (Cushing’s disease). Neuromuscul Disord 2006; 16:737-44. [PMID: 17005399 DOI: 10.1016/j.nmd.2006.07.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Revised: 06/29/2006] [Accepted: 07/14/2006] [Indexed: 11/26/2022]
Abstract
Fifteen horses with pituitary pars intermedia dysfunction were studied. The horses were of various breeds and between 15 and 28 years of age. Control horses matched for breed and age were studied for comparison. Evaluations included complete blood cell count and serum biochemical analysis, electromyography, and gluteus medius muscle biopsies for histochemical, morphometric, and ultrastructural analysis. No differences were found between groups of horses on routine laboratory analysis or electromyography. We demonstrated that muscle wasting in diseased horses was the result of atrophy of types 2A and 2B muscle fibers and loss of type 2B myofibers. Mild non-specific non-inflammatory myopathic alterations such as myofiber size variation, internal nuclei, perimysial, endomysial and sarcoplasmic fat accumulation were observed. At the ultrastructural level, subsarcolemmal mitochondrial accumulation and increased lipid droplets were evident. Similar to other species, this study confirmed atrophy of type 2 fibers as the cause of muscle mass loss in horses with Cushing's disease.
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Affiliation(s)
- M Aleman
- Department of Veterinary Medicine and Epidemiology, University of California, Davis, USA.
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38
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Wessmann A, Volk HA, Shelton GD, Chandler KE, Baines S, Cappello R. Portosystemic shunt associated with severe episodic weakness. J Vet Intern Med 2006; 20:1042-4. [PMID: 16955838 DOI: 10.1892/0891-6640(2006)20[1042:psawse]2.0.co;2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- A Wessmann
- North Downs Specialist Referrals, Caterham, Surrey, UK.
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Affiliation(s)
- L A Wieczorek
- Centre for Small Animal Studies, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk cb8 7uu
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Lujan Feliu-Pascual A, Lujan Feliu-Pascual A, Shelton GD, Targett MP, Long SN, Comerford EJ, McMillan C, Davies D, Rusbridge C, Mellor D, Chang KC, Anderson TJ. Inherited myopathy of great Danes. J Small Anim Pract 2006; 47:249-54. [PMID: 16674719 DOI: 10.1111/j.1748-5827.2006.00073.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A hereditary, non-inflammatory myopathy occurring in young great Danes with distinctive histological features in muscle biopsy specimens is reviewed. Onset of clinical signs is usually before one year of age and both sexes are affected. Clinical signs are characterised by exercise intolerance, muscle wasting, and an exercise-induced tremor. Although most affected dogs have a severe form of the disease, occasional dogs may have a less pronounced form and survive into adulthood with an acceptable quality of life. Litters containing affected puppies are born to clinically unaffected parents, and an autosomal recessive pattern of inheritance is likely. All recorded cases have had fawn or brindle coat coloration. Elevated serum creatinine kinase concentrations and spontaneous electrical activity in skeletal muscles are frequently found. While originally reported (Targett and others 1994) as a central core myopathy in this breed, the histochemical characteristics of the distinct cytoarchitectural structures differ from those of the well-characterised central core myopathy in human beings. In fact, these structures differ from any known myopathy in human beings and likely represents a unique non-inflammatory myopathy affecting dogs. Until this myopathy is characterised further, the name inherited myopathy in great Danes is suggested.
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Affiliation(s)
- A Lujan Feliu-Pascual
- Comparative Neuromuscular Laboratory, University of California-San Diego, La Jolla, CA 92093-0709, USA
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Abstract
The clinical phenotype of hereditary myopathy of labrador retrievers is consistent, but the pathological changes within muscle biopsy specimens can vary from type 1 fibre predominance (type 2 fibre deficiency) to dystrophic changes or overt neurogenic atrophy. The condition shares many clinical and pathological features with the mildest form of human childhood spinal muscular atrophy, and the survival motor neuron gene was therefore evaluated in dogs with the disease. Direct sequencing and comparisons of cdna from the gene in seven labrador retrievers homozygous for the disease and four control dogs revealed no nucleotide mutations leading to changes in the deduced amino acid sequences. A single polymorphism was detected in two of the seven affected dogs, which was characterised by a nucleotide substitution at amino acid position 1155 within the non-coding 3' untranslated region of exon 8. Northern blot analysis indicated that there were no differences in the steady state levels of mrna from the gene of the affected labrador retrievers and control dogs.
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Affiliation(s)
- S L Green
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford CA 94305, USA
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42
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Aleman M, Lecouteur RA, Nieto JE, Williams DC, Stanke NJ, Shelton GD. Sarcoplasmic masses in equine skeletal muscle. Neuromuscul Disord 2005; 15:147-53. [PMID: 15694136 DOI: 10.1016/j.nmd.2004.10.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2004] [Revised: 10/07/2004] [Accepted: 10/13/2004] [Indexed: 11/26/2022]
Abstract
Sarcoplasmic masses in humans have been associated with various myopathies, although the significance remains elusive. Similar structures have also been observed in equine muscle. The aim of this study was to determine the frequency of such structures in normal and abnormal equine muscle, and to characterize these structures using histological, histochemical, immunohistochemical, ultrastructural, and morphometric analyses. The histological and histochemical appearance was similar to that of human sarcoplasmic masses with a central or subsarcolemmal distribution. Of interest was a predilection for the gluteus medius muscle in younger horses and type 2B fibers. Ultrastructurally they contained disorganized myofibrils and other cellular components that were not membrane bound and were present in both normal and abnormal equine muscle without a specific disease association, suggesting they are a non-pathological degenerative structure. The relatively frequent occurrence of sarcoplasmic masses in horses may make this species a good model for studying the pathogenesis of these structures.
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Affiliation(s)
- M Aleman
- Department of Veterinary Surgical and Radiological Sciences, University of California, Tupper Hall 2112, One Shields Avenue, Davis 95616, USA.
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43
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Abstract
A two-year-old, intact female Sussex spaniel was presented with signs of exercise intolerance. Pre- and post-exercise serum lactate and pyruvate concentrations and urinary organic acid screening supported a diagnosis of pyruvate dehydrogenase deficiency, as previously reported in this breed. Dietary therapy was initiated for six months, during which time there was no reported clinical deterioration. A full neurological examination and repeat evaluation of lactate and pyruvate concentrations before and after exercise was conducted one year after diagnosis, at which time the patient had been without dietary modification for six months and had developed more severe exercise intolerance along with evidence of central nervous system dysfunction.
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Affiliation(s)
- C J Abramson
- Centre for Small Animal Studies, Animal Health Trust, Suffolk CB8 7UU
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44
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Abstract
A European case of laminin alpha2 deficiency-associated muscular dystrophy in a 12-month-old, female Maine coon pedigree cat is reported. The history and eventual clinical presentation of this cat differed from those of two cats reported in the USA. In this case, the myopathy was characterised by progressively worsening weakness, muscle atrophy and joint contracture. Tendon reflexes were diminished, and motor nerve conduction velocities were slowed. Muscle biopsy demonstrated a dystrophic phenotype with endomysial fibrosis. Occasional thinly myelinated nerve fibres were present within a peripheral nerve specimen. Poorly myelinated fibres were also found at the root level on necropsy specimens. Immunohistochemical staining revealed the absence of laminin alpha2. The cat's family history did not indicate genetic transmission of the disease.
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Affiliation(s)
- L Poncelet
- Department of Anatomy and Embryology, Faculty of Medicine, Free University of Brussels, route de Lennik 808, B-1070 Brussels, Belgium
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Abstract
The natural course of autoimmune canine MG was determined in 53 dogs with muscular weakness and a positive acetylcholine receptor antibody titer. Dogs were treated with anticholinesterase therapy, without immunosuppression. Spontaneous clinical and immunologic remission occurred in 47 of 53 dogs within an average of 6.4 months. Neoplasia was identified in the six dogs that did not spontaneously remit. This study questions the value of using canine MG in studies designed to assess the effect of immunotherapies.
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Affiliation(s)
- G D Shelton
- Department of Pathology, University of California San Diego, La Jolla, CA 92093-0612, USA.
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Zhou Q, Chu PH, Huang C, Cheng CF, Martone ME, Knoll G, Shelton GD, Evans S, Chen J. Ablation of Cypher, a PDZ-LIM domain Z-line protein, causes a severe form of congenital myopathy. J Cell Biol 2001; 155:605-12. [PMID: 11696561 PMCID: PMC2198871 DOI: 10.1083/jcb.200107092] [Citation(s) in RCA: 228] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cypher is a member of a recently emerging family of proteins containing a PDZ domain at their NH(2) terminus and one or three LIM domains at their COOH terminus. Cypher knockout mice display a severe form of congenital myopathy and die postnatally from functional failure in multiple striated muscles. Examination of striated muscle from the mutants revealed that Cypher is not required for sarcomerogenesis or Z-line assembly, but rather is required for maintenance of the Z-line during muscle function. In vitro studies demonstrated that individual domains within Cypher localize independently to the Z-line via interactions with alpha-actinin or other Z-line components. These results suggest that Cypher functions as a linker-strut to maintain cytoskeletal structure during contraction.
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Affiliation(s)
- Q Zhou
- Institute of Molecular Medicine and Department of Medicine, University of California at San Diego School of Medicine, La Jolla, CA 92093, USA
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47
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O'Brien DP, Johnson GC, Liu LA, Guo LT, Engvall E, Powell HC, Shelton GD. Laminin alpha 2 (merosin)-deficient muscular dystrophy and demyelinating neuropathy in two cats. J Neurol Sci 2001; 189:37-43. [PMID: 11535231 DOI: 10.1016/s0022-510x(01)00559-7] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We report laminin alpha 2 (merosin) deficiency associated with muscular dystrophy and demyelinating neuropathy in two cats. The cats developed progressive muscle weakness, and atrophy. Either hypotonia or contractures resulted in recumbency, necessitating euthanasia. Muscle biopsies showed dystrophic changes including marked endomysial fibrosis, myofiber necrosis, variability of fiber size, and perimysial lipid accumulation. Immunohistochemistry showed that laminin alpha 2 chain was absent or reduced, while dystrophin and all the components of the dystrophin-associated glycoprotein complex were present and normal. One cat was examined in detail. Motor nerve conduction velocity (MNCV) was decreased, and ultrastructurally the peripheral nerves showed Schwann cell degeneration and demyelination. Brain imaging was not performed, but white matter changes were not apparent in the brain at necropsy. The disease in these cats is similar to primary or secondary merosin (laminin alpha 2)-deficient congenital muscular dystrophy (CMD) in humans and to dystrophia muscularis in mice.
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Affiliation(s)
- D P O'Brien
- Department of Veterinary Medicine and Surgery, University of Missouri, 379 E. Campus Drive, Columbia, MO 65211, USA.
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Shelton GD, Liu LA, Guo LT, Smith GK, Christiansen JS, Thomas WB, Smith MO, Kline KL, March PA, Flegel T, Engvall E. Muscular dystrophy in female dogs. J Vet Intern Med 2001; 15:240-4. [PMID: 11380033 DOI: 10.1892/0891-6640(2001)015<0240:mdifd>2.3.co;2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The most common form of muscular dystrophy in dogs and humans is caused by mutations in the dystrophin gene. The dystrophin gene is located on the X chromosome, and, therefore, disease-causing mutations in dystrophin occur most often in males. Therefore, females with dystrophin deficiency or other forms of muscular dystrophy may be undiagnosed or misdiagnosed. Immunohistochemistry was used to analyze dystrophin and a number of other muscle proteins associated with muscular dystrophy in humans, including sarcoglycans and laminin alpha2, in muscle biopsy specimens from 5 female dogs with pathologic changes consistent with muscular dystrophy. The female dogs were presented with a variety of clinical signs including generalized weakness, muscle wasting, tremors, exercise intolerance, gait abnormalities, and limb deformity. Serum creatine kinase activity was variably high. One dog had no detectable dystrophin in the muscle; another was mosaic, with some fibers normal and others partly dystrophin-deficient. A 3rd dog had normal dystrophin but no detectable laminin alpha2. Two dogs could not be classified. This study demonstrates the occurrence of dystrophin- and laminin alpha2-associated muscular dystrophy and the difficulty in clinical diagnosis of these disorders in female dogs.
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Affiliation(s)
- G D Shelton
- Department of Pathology, University of California, San Diego, La Jolla 92093-0612, USA.
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Anderson MJ, Shelton GD, Cavenee WK, Arden KC. Embryonic expression of the tumor-associated PAX3-FKHR fusion protein interferes with the developmental functions of Pax3. Proc Natl Acad Sci U S A 2001; 98:1589-94. [PMID: 11171995 PMCID: PMC29301 DOI: 10.1073/pnas.98.4.1589] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A unique chromosomal translocation involving the genes PAX3 and FKHR is characteristic of most human alveolar rhabdomyosarcomas. The resultant chimeric protein fuses the PAX3 DNA-binding domains to the transactivation domain of FKHR, suggesting that PAX3-FKHR exerts its role in alveolar rhabdomyosarcomas through dysregulation of PAX3-specific target genes. Here, we have produced transgenic mice in which PAX3-FKHR expression was driven by mouse Pax3 promoter/enhancer sequences. Five independent lines expressed PAX3-FKHR in the dorsal neural tube and lateral dermomyotome. Each line exhibited phenotypes that correlated with PAX3-FKHR expression levels and predominantly involved pigmentary disturbances of the abdomen, hindpaws, and tail, with additional neurological related alterations. Phenotypic severity could be increased by reducing Pax3 levels through matings with Pax3-defective Splotch mice, and interference between PAX3 and PAX3-FKHR was apparent in transcription reporter assays. These data suggest that the tumor-associated PAX3-FKHR fusion protein interferes with normal Pax3 developmental functions as a prelude to transformation.
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Affiliation(s)
- M J Anderson
- Ludwig Institute for Cancer Research, University of California at San Diego, La Jolla, CA 92093-0660, USA.
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50
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Abstract
Similar to human autoimmune myasthenia gravis (MG), canine MG occurs spontaneously and is associated with autoantibodies against the nicotinic acetylcholine receptor (AChR). In addition to AChR, human MG patients with thymoma or late-onset MG have antibodies against titin and ryanodine receptor (RyR). The objective of this study was to establish if dogs with confirmed MG (AChR antibody titer >0.6 nmol/l) also developed titin and RyR antibodies and identify possible associations with thymoma, late age of onset, or severity of clinical signs. Sera from dogs (n=430) with previously diagnosed autoimmune MG (N=415), other immune-mediated neuromuscular disorders including polymyositis (PM) and masticatory muscle myositis (N=5), and control dogs (N=10) were evaluated for the presence of titin antibodies in ELISA using MGT-30 as antigen, a peptide representing the main immunogenic region (MIR) for human titin antibodies. Titin antibody positive sera were further examined for RyR antibodies in Western blots using a RyR fusion protein (pc2-RyR) as antigen, which covers the MIR for human MG sera. Titin antibodies were found in sera of 80/430 dogs. Thymoma was present in 11/80 and age of onset was after 4 years in 66/80 titin positive dogs. Two of the titin positive dogs had PM. RyR antibodies were found in 13/80 sera (8/13 thymoma, 12/13 age of onset after 4 years, and 1/13 PM). Neither titin nor RyR antibodies were found in sera of healthy control dogs. Acute fulminating MG was described in five dogs with both titin and RyR antibodies. From these studies we conclude that titin and RyR antibodies in canine and human MG have a similar association with thymoma, late-onset MG, and possibly with more severe forms of MG.
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Affiliation(s)
- G D Shelton
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093-0612, USA.
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