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Bester EG, Kitshoff AM, Botha WJ, van Wilpe E, du Plessis L, Williams J. Nemaline myopathy in a six-month-old Pomeranian dog. J S Afr Vet Assoc 2022. [DOI: 10.36303/jsava.2022.93.1.498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Affiliation(s)
- EG Bester
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria,
South Africa
| | - AM Kitshoff
- Department of Companion Animal Clinical Studies, Faculty of Veterinary Science, University of Pretoria,
South Africa
| | - WJ Botha
- Department of Small Animal Medicine Clinic, Panorama Veterinary Clinic and Specialist Centre,
South Africa
| | - E van Wilpe
- Laboratory for Microscopy and Microanalysis, Faculty of Natural and Agricultural Sciences, University of Pretoria,
South Africa
| | - L du Plessis
- Electron Microscope Unit, Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria,
South Africa
| | - J Williams
- Section of Pathology, Department of Paraclinical Sciences, Faculty of Veterinary Science, University of Pretoria,
South Africa
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2
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Kelly D, Quinn R. Non-inflammatory joint effusions as a presenting sign of hypothyroidism in a dog. J Small Anim Pract 2021; 63:159-162. [PMID: 34585404 DOI: 10.1111/jsap.13431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 08/20/2021] [Accepted: 09/06/2021] [Indexed: 11/29/2022]
Abstract
Non-inflammatory joint effusion with characteristically increased synovial fluid viscosity is a rare but well-recognised rheumatic manifestation of hypothyroidism in people and based on the literature search, this is the first report of the condition in dogs. A 2-year-old Pyrenean Mountain dog presented for lameness and multiple joint effusions. CT confirmed effusions affecting multiple limb joints along with delayed closure of multiple physes. Synovial fluid analysis from the effused joints showed no evidence of inflammation but the fluid viscosity was markedly increased. Serum total thyroxine concentration was decreased, thyroid-stimulating hormone concentration was increased and antithyroglobulin autoantibody measurement returned a positive result. Oral levothyroxine supplementation resulted in relatively rapid and complete resolution of the clinical signs, in association with attaining a euthyroid state. Follow-up examination and CT six months later confirmed resolution of the joint effusions and significant improvement or resolution of the other documented skeletal changes.
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Affiliation(s)
- D Kelly
- Southern Counties Veterinary Specialists, Ringwood, UK
| | - R Quinn
- Southern Counties Veterinary Specialists, Ringwood, UK
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3
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Southard T, Kelly K, Armien AG. Myocardial protein aggregates in pet guinea pigs. Vet Pathol 2021; 59:157-163. [PMID: 34530659 DOI: 10.1177/03009858211042586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A retrospective study of guinea pigs submitted for necropsy revealed intracytoplasmic inclusions in the cardiomyocytes of 26 of 30 animals. The inclusions were found with approximately the same frequency in male and female guinea pigs and were slightly more common in older animals. In most cases, the animals did not have clinical signs or necropsy findings suggestive of heart failure, and the cause of death or reason for euthanasia was attributed to concurrent disease processes. However, the 4 guinea pigs with the highest inclusion body burden all had pulmonary edema, sometimes with intra-alveolar hemosiderin-laden macrophages, suggestive of heart failure. The inclusions were found in both the left and right ventricular myocardium, mainly in the papillary muscles, but were most common in the right ventricular free wall. No inclusions were detected in the atrial myocardium or in skeletal muscle. The inclusions did not stain with Congo red or periodic acid-Schiff. Electron microscopy revealed dense aggregates of disorganized myofilaments and microtubules that displaced and compressed the adjacent organelles. By immunohistochemistry, there was some scattered immunoreactivity for desmin and actin at the periphery of the inclusions and punctate actin reactivity within the aggregates. The inclusions did not react with antibodies to ubiquitin or cardiac myosin, but were variably reactive for alpha B crystallin, a small heat shock chaperone protein. The inclusions were interpreted as evidence of impaired proteostasis.
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4
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Thomas-Hollands A, Shelton GD, Guo LT, Loughran K, Kaiman G, A Hutton T, Walsh KA. Congenital dyserythropoiesis and polymyopathy without cardiac disease in male Labrador retriever littermates. J Vet Intern Med 2021; 35:2409-2414. [PMID: 34227150 PMCID: PMC8478025 DOI: 10.1111/jvim.16214] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 11/30/2022] Open
Abstract
Background Two Labrador retriever littermates were identified based on incidentally noted marked microcytosis and inappropriate metarubricytosis. Muscle atrophy was noted and associated with distinctive pathological findings in biopsy samples from 1 dog studied. The disorder represents a rare clinical entity of suspected congenital dyserythropoiesis and polymyopathy. Clinicopathologic changes were similar to a previously reported syndrome of congenital dyserythropoiesis, congenital polymyopathy, and cardiac disease in 3 related English Springer Spaniel (ESS) dogs, but the dogs reported here did not have apparent cardiac disease. Interventions Bone marrow aspiration, electromyography, muscle biopsies, and an echocardiogram were performed on dog 1. Results supported dyserythropoiesis and congenital polymyopathy similar to reports in ESS dogs, but did not identify obvious cardiac disease. Conclusion The clinicopathologic changes of dyserythropoiesis and polymyopathy provide an easily recognizable phenotype for what appears to be a low morbidity syndrome. Early recognition may decrease unnecessary testing or euthanasia.
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Affiliation(s)
- Alison Thomas-Hollands
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - G Diane Shelton
- Department of Pathology, University of California San Diego, La Jolla, California, USA
| | - Ling T Guo
- Department of Pathology, University of California San Diego, La Jolla, California, USA
| | - Kerry Loughran
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Gregory Kaiman
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Tabitha A Hutton
- Metropolitan Veterinary Associates, Norristown, Pennsylvania, USA
| | - Koranda A Walsh
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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5
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Kamio K, Takahashi Y, Ishihara K, Sekiya A, Kato S, Shimanuki I, Ide M, Furuoka H. Centronuclear Myopathy with Abundant Nemaline Rods in a Japanese Black and Hereford Crossbred Calf. J Comp Pathol 2019; 174:8-12. [PMID: 31955807 DOI: 10.1016/j.jcpa.2019.10.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 09/17/2019] [Accepted: 10/19/2019] [Indexed: 10/25/2022]
Abstract
Histopathological examination was performed on skeletal and diaphragmatic muscles from an 8-month-old male crossbred calf showing abnormal gait and tremor of the hindlimbs. There were numerous round fibres with centrally placed nuclei forming nuclear chains in longitudinal sections, associated with interstitial fibrosis or adipose tissue infiltration. On nicotinamide adenine dinucleotide tetrazolium reductase (NADH-TR) staining, some muscle fibres in severe lesions showed a spoke-like appearance due to a radial arrangement of sarcoplasmic strands. Additionally, increased NADH-TR activity in the subsarcolemmal structures, appearingas ring-like or necklace-like forms, were observed. Transmission electron microscopy revealed dilated sarcoplasmic reticulum and variably shaped electron-dense inclusions consisting of myofibrillar streams. Another prominent feature was the existence of numerous nemaline rods within muscle fibres; these were stained red by Gomori's trichrome stain. Immunohistochemistry revealed that the nemaline rods showed strong immunoreactivity with α-actinin and desmin antibodies. Electron microscopically, these structures were composed of dense-homogeneous material and continuous with the Z disk. The case was diagnosed as centronuclear myopathy with increased nemaline rods.
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Affiliation(s)
- K Kamio
- Division of Veterinary Sciences, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Japan
| | - Y Takahashi
- Division of Veterinary Sciences, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Japan
| | - K Ishihara
- Division of Veterinary Sciences, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Japan
| | - A Sekiya
- Division of Veterinary Sciences, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Japan
| | - S Kato
- Division of Veterinary Sciences, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Japan
| | - I Shimanuki
- Tokachi Agricultural Mutual Aid Association, Obihiro, Japan
| | - M Ide
- Tokachi Agricultural Mutual Aid Association, Obihiro, Japan
| | - H Furuoka
- Division of Veterinary Sciences, Department of Veterinary Medicine, Obihiro University of Agriculture and Veterinary Medicine, Japan.
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6
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Fox MD, Carson VJ, Feng HZ, Lawlor MW, Gray JT, Brigatti KW, Jin JP, Strauss KA. TNNT1 nemaline myopathy: natural history and therapeutic frontier. Hum Mol Genet 2019; 27:3272-3282. [PMID: 29931346 DOI: 10.1093/hmg/ddy233] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/06/2018] [Indexed: 02/03/2023] Open
Abstract
We describe the natural history of 'Amish' nemaline myopathy (ANM), an infantile-onset, lethal disease linked to a pathogenic c.505G>T nonsense mutation of TNNT1, which encodes the slow fiber isoform of troponin T (TNNT1; a.k.a. TnT). The TNNT1 c.505G>T allele has a carrier frequency of 6.5% within Old Order Amish settlements of North America. We collected natural history data for 106 ANM patients born between 1923 and 2017. Over the last two decades, mean age of molecular diagnosis was 16 ± 27 days. TNNT1 c.505G>T homozygotes were normal weight at birth but failed to thrive by age 9 months. Presenting neonatal signs were axial hypotonia, hip and shoulder stiffness, and tremors, followed by progressive muscle weakness, atrophy and contractures. Affected children developed thoracic rigidity, pectus carinatum and restrictive lung disease during infancy, and all succumbed to respiratory failure by 6 years of age (median survival 18 months, range 0.2-66 months). Muscle histology from two affected children showed marked fiber size variation owing to both Type 1 myofiber smallness (hypotrophy) and Type 2 fiber hypertrophy, with evidence of nemaline rods, myofibrillar disarray and vacuolar pathology in both fiber types. The truncated slow TNNT1 (TnT) fragment (p.Glu180Ter) was undetectable in ANM muscle, reflecting its rapid proteolysis and clearance from sarcoplasm. Similar functional and histological phenotypes were observed in other human cohorts and two transgenic murine models (Tnnt1-/- and Tnnt1 c.505G>T). These findings have implications for emerging molecular therapies, including the suitably of TNNT1 gene replacement for newborns with ANM or other TNNT1-associated myopathies.
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Affiliation(s)
- Michael D Fox
- Clinic for Special Children, Strasburg, PA, USA
- Department of Pediatrics, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
- Diagnostic Referral Division, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | | | - Han-Zhong Feng
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Michael W Lawlor
- Department of Pathology and Laboratory Medicine and Neuroscience Research Center, The Medical College of Wisconsin, Milwaukee, WI, USA
| | - John T Gray
- Audentes Therapeutics, San Francisco, CA, USA
| | | | - J-P Jin
- Department of Physiology, Wayne State University School of Medicine, Detroit, MI, USA
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7
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Dettwiler M, Sydler T, Klausmann S, Beckmann K, Hilbe M. Nemaline myopathy diagnosed in two young Border collies in formalin‐fixed paraffin‐embedded muscle samples using conventional stains. VETERINARY RECORD CASE REPORTS 2018. [DOI: 10.1136/vetreccr-2018-000711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
| | - Titus Sydler
- Institute of Veterinary PathologyZurichSwitzerland
| | | | - Katrin Beckmann
- Department fur KleintiereUniversitat ZurichZurichSwitzerland
| | - Monika Hilbe
- Institute of Veterinary PathologyZurichSwitzerland
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8
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Taylor S, Shmon C, Su L, Epp T, Minor K, Mickelson J, Patterson E, Shelton GD. Evaluation of Dogs with Border Collie Collapse, Including Response to Two Standardized Strenuous Exercise Protocols. J Am Anim Hosp Assoc 2016; 52:281-90. [PMID: 27487345 DOI: 10.5326/jaaha-ms-6361] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Clinical and metabolic variables were evaluated in 13 dogs with border collie collapse (BCC) before, during, and following completion of standardized strenuous exercise protocols. Six dogs participated in a ball-retrieving protocol, and seven dogs participated in a sheep-herding protocol. Findings were compared with 16 normal border collies participating in the same exercise protocols (11 retrieving, five herding). Twelve dogs with BCC developed abnormal mentation and/or an abnormal gait during evaluation. All dogs had post-exercise elevations in rectal temperature, pulse rate, arterial blood pH, PaO2, and lactate, and decreased PaCO2 and bicarbonate, as expected with strenuous exercise, but there were no significant differences between BCC dogs and normal dogs. Electrocardiography demonstrated sinus tachycardia in all dogs following exercise. Needle electromyography was normal, and evaluation of muscle biopsy cryosections using a standard panel of histochemical stains and reactions did not reveal a reason for collapse in 10 dogs with BCC in which these tests were performed. Genetic testing excluded the dynamin-1 related exercise-induced collapse mutation and the V547A malignant hyperthermia mutation as the cause of BCC. Common reasons for exercise intolerance were eliminated. Although a genetic basis is suspected, the cause of collapse in BCC was not determined.
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Affiliation(s)
- Susan Taylor
- From the Department of Small Animal Clinical Sciences (S.T., C.S., L.S.) and the Department of Large Animal Clinical Sciences (T.E.), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada; the University of Minnesota, Minneapolis, MN (K.M., J.M., E.P.); and the Comparative Neuromuscular Laboratory, Department of Pathology, University of California-San Diego, La Jolla, CA (G.D.S.)
| | - Cindy Shmon
- From the Department of Small Animal Clinical Sciences (S.T., C.S., L.S.) and the Department of Large Animal Clinical Sciences (T.E.), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada; the University of Minnesota, Minneapolis, MN (K.M., J.M., E.P.); and the Comparative Neuromuscular Laboratory, Department of Pathology, University of California-San Diego, La Jolla, CA (G.D.S.)
| | - Lillian Su
- From the Department of Small Animal Clinical Sciences (S.T., C.S., L.S.) and the Department of Large Animal Clinical Sciences (T.E.), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada; the University of Minnesota, Minneapolis, MN (K.M., J.M., E.P.); and the Comparative Neuromuscular Laboratory, Department of Pathology, University of California-San Diego, La Jolla, CA (G.D.S.)
| | - Tasha Epp
- From the Department of Small Animal Clinical Sciences (S.T., C.S., L.S.) and the Department of Large Animal Clinical Sciences (T.E.), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada; the University of Minnesota, Minneapolis, MN (K.M., J.M., E.P.); and the Comparative Neuromuscular Laboratory, Department of Pathology, University of California-San Diego, La Jolla, CA (G.D.S.)
| | - Katie Minor
- From the Department of Small Animal Clinical Sciences (S.T., C.S., L.S.) and the Department of Large Animal Clinical Sciences (T.E.), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada; the University of Minnesota, Minneapolis, MN (K.M., J.M., E.P.); and the Comparative Neuromuscular Laboratory, Department of Pathology, University of California-San Diego, La Jolla, CA (G.D.S.)
| | - James Mickelson
- From the Department of Small Animal Clinical Sciences (S.T., C.S., L.S.) and the Department of Large Animal Clinical Sciences (T.E.), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada; the University of Minnesota, Minneapolis, MN (K.M., J.M., E.P.); and the Comparative Neuromuscular Laboratory, Department of Pathology, University of California-San Diego, La Jolla, CA (G.D.S.)
| | - Edward Patterson
- From the Department of Small Animal Clinical Sciences (S.T., C.S., L.S.) and the Department of Large Animal Clinical Sciences (T.E.), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada; the University of Minnesota, Minneapolis, MN (K.M., J.M., E.P.); and the Comparative Neuromuscular Laboratory, Department of Pathology, University of California-San Diego, La Jolla, CA (G.D.S.)
| | - G Diane Shelton
- From the Department of Small Animal Clinical Sciences (S.T., C.S., L.S.) and the Department of Large Animal Clinical Sciences (T.E.), Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada; the University of Minnesota, Minneapolis, MN (K.M., J.M., E.P.); and the Comparative Neuromuscular Laboratory, Department of Pathology, University of California-San Diego, La Jolla, CA (G.D.S.)
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9
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Eminaga S, Cherubini GB, Shelton GD. Centronuclear myopathy in a Border collie dog. J Small Anim Pract 2012; 53:608-12. [DOI: 10.1111/j.1748-5827.2012.01265.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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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10
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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] [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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11
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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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Taylor SM, Shmon CL, Adams VJ, Mickelson JR, Patterson ENE, Shelton GD. Evaluations of labrador retrievers with exercise-induced collapse, including response to a standardized strenuous exercise protocol. J Am Anim Hosp Assoc 2009; 45:3-13. [PMID: 19122058 DOI: 10.5326/0450003] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Clinical and metabolic variables were evaluated in 14 Labrador retrievers with exercise-induced collapse (EIC) before, during, and following completion of a standardized strenuous exercise protocol. Findings were compared with previously reported variables from 14 normal Labrador retrievers that participated in the same protocol. Ten of 14 dogs with EIC developed an abnormal gait during evaluation, and these dogs were significantly more tachycardic and had a more severe respiratory alkalosis after exercise compared to the normal dogs. Muscle biopsy characteristics and sequential lactate and pyruvate concentrations were normal. Genetic testing and linkage analysis excluded malignant hyperthermia as the cause of EIC. Common causes of exercise intolerance were eliminated, but the cause of collapse in EIC was not determined.
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Affiliation(s)
- Susan M Taylor
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B4, Canada
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13
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Scott-Moncrieff JC. Clinical Signs and Concurrent Diseases of Hypothyroidism in Dogs and Cats. Vet Clin North Am Small Anim Pract 2007; 37:709-22, vi. [PMID: 17619007 DOI: 10.1016/j.cvsm.2007.03.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Canine hypothyroidism may present with a wide range of clinical signs. The most common clinical signs are those of a decreased metabolic rate and dermatologic manifestations; however, many other clinical signs have been associated with hypothyroidism. There is strong evidence for a causal relation between hypothyroidism and a variety of neurologic abnormalities; however, the association between hypothyroidism and other manifestations, such as reproductive dysfunction, clinical heart disease, and behavioral abnormalities, is less compelling. Further studies are necessary to determine the full spectrum of disorders caused by hypothyroidism.
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Affiliation(s)
- J Catharine Scott-Moncrieff
- Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Purdue University, VCS/LYNN, 625 Harrison Street, West Lafayette, IN 47907-2026, USA.
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14
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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] [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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15
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Kube SA, Vernau KM, LeCouteur RA, Mizisin AP, Shelton GD. Congenital myopathy with abundant nemaline rods in a cat. Neuromuscul Disord 2006; 16:188-91. [PMID: 16487709 DOI: 10.1016/j.nmd.2005.12.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2005] [Revised: 12/15/2005] [Accepted: 12/20/2005] [Indexed: 11/16/2022]
Abstract
Nemaline myopathy is associated with rod-shaped structures in muscle fibers. At least seven distinct clinical forms have been described in humans and mutations have been identified in five different thin-filament genes. Only a few cases of spontaneously occurring nemaline myopathy have been reported in animals and include an adult-onset form in a family of cats and an early-onset form in a dog. Here, we describe a 2-year-old male, neutered, domestic shorthaired cat that was referred to the Veterinary Medical Teaching Hospital, University of California-Davis, for evaluation of chronic, progressive weakness, and fine tremors. Neurologic deficits were restricted to the neuromuscular system. Electromyography showed mild to moderate diffuse spontaneous activity. Although rod bodies were prominent on light and electron microscopic evaluation of biopsies from several muscles, sarcoplasmic accumulations of dystrophin, desmin, and spectrin also were identified by immunohistochemistry. These findings may represent the occurrence of rod bodies in conjunction with a protein-aggregate myopathy.
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Affiliation(s)
- Stephanie A Kube
- Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA
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16
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Shelton GD, Engvall E. Canine and feline models of human inherited muscle diseases. Neuromuscul Disord 2005; 15:127-38. [PMID: 15694134 DOI: 10.1016/j.nmd.2004.10.019] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2004] [Revised: 09/23/2004] [Accepted: 10/13/2004] [Indexed: 10/25/2022]
Abstract
Animal models are of immense importance for studying mechanisms of disease and testing new therapies, and rodents have been used extensively in the field of neuromuscular disorders. Mice and rats can be genetically manipulated to over-express or not express genes that are important to muscle function, and these animals can be available in large numbers for analysis. Other species, such as cats and dogs, cannot be manipulated in the same ways or be used in large numbers, but they have spontaneously occurring muscle diseases with clinical presentations more closely resembling those of the human disorders. Therefore, cats and dogs may become valuable as intermediate disease models. This review focuses on canine and feline models of human inherited muscle diseases with comparisons to rodent models and an emphasis on the muscular dystrophies.
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Affiliation(s)
- G Diane Shelton
- Department of Pathology, University of California, San Diego, La Jolla, CA 92093-0709, USA.
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17
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Affiliation(s)
- Scott J Schatzberg
- Cornell University Hospital for Animals, Cornell University, Box 35, Ithaca, NY 14853, USA.
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18
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Abstract
Accurate diagnosis of the many causes of acute and chronic peripheral neuropathy in the dog presents a challenging prospect for any clinician. Being able to accurately localize the observed neurologic signs to the peripheral nervous system is the first challenge. Once this is accomplished, a logical series of diagnostic steps should be pursued so as to have the best chance of reaching a final etiologic diagnosis. Specific therapy can then be instituted to attempt to halt or, in some cases, reverse the peripheral nerve dysfunction.
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Affiliation(s)
- Paul A Cuddon
- Veterinary Specialists of Northern Colorado, Loveland 80538, USA.
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19
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Abstract
It is certain that more inherited neuromuscular disorders of dogs and cats will be identified as the ability of practicing veterinarians to recognize disorders of muscle, nerve, and neuromuscular junction improves and newer diagnostic tests become available. Two specific points are critical. Before DNA-based genetic tests and specific therapies can be developed, an accurate description of the problem, clinically and histopathologically, must be performed. This is particularly important for the accuracy of a pedigree analysis, because inclusion of dogs with unrelated problems would alter the interpretation. Second, animals with inherited breed-associated disease should not be bred for generation of companion animals.
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Affiliation(s)
- G Diane Shelton
- Department of Pathology, School of Medicine, University of California, San Diego, La Jolla 92093-0612, USA.
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20
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Abstract
Biopsy of muscle and nerve is an essential component of the diagnostic plan for animals with suspected neuromuscular disease. This article includes descriptions of the biopsy procedures and information regarding appropriate biopsy site selection and correct handling and processing of the tissues. The normal and pathological appearance of muscle and nerve using routine histochemical and histological techniques are described and illustrated emphasizing the basic myopathic and neuropathic responses of the neuromuscular system.
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Affiliation(s)
- Peter J Dickinson
- Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis 95616, USA.
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21
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Abstract
Many of the endocrine and metabolic myopathies have no unique features, and for most clinicians, it is not possible to remember the clinical nuances of all the specific abnormalities and deficiencies responsible for these myopathies. This can make this group of diseases difficult to suspect. It is more important to recognize the general features of myopathic disease and to consider muscle biopsies as a preliminary diagnostic technique, with the potential for further investigation if a myopathy is confirmed.
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Affiliation(s)
- Simon R Platt
- Neurology/Neurosurgery Unit, The Animal Health Trust, Centre for Small Animal Studies, Newmarket, Suffolk, England.
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22
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23
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Abstract
A variety of disorders affect the muscles or the neuromuscular junction of dogs and cats, most often causing weakness, exercise intolerance, and muscular pain or atrophy. The myopathies are infectious, immune-mediated, inherited or acquired secondary to systemic disease. Acquired myasthenia gravis is a common disorder of the neuromuscular junction, which clinically resembles a myopathy. Reaching a specific diagnosis is essential to determine optimal therapy and prognosis for each of the commonly recognized disorders.
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Affiliation(s)
- S M Taylor
- Department of Veterinary Internal Medicine, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, Canada
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