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Jahn P, Dobešová D, Brumarová R, Tóthová K, Kopecká A, Friedecký D. Dynamics of acylcarnitines, hypoglycin A, méthylènecyclopropylglycine and their metabolites in a Kladruber stallion with atypical myopathy. Vet Q 2022; 42:183-191. [PMID: 36114619 PMCID: PMC9518284 DOI: 10.1080/01652176.2022.2126537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Equine atypical myopathy (AM also referred to as multiple acyl-CoA dehydrogenases deficiency [MADD]) is thought to be caused by toxins metabolized from hypoglycin A (HGA) and méthylènecyclopropylglycine (MCPrG). HGA is contained in the seeds and seedlings of the sycamore tree (Acer pseudoplatanus); MCPrG has so far only been confirmed in seeds. Among other things, these substances can disrupt the fatty acids β-oxidation pathway with the subsequent accumulation of certain acylcarnitines. The tentative diagnosis is based on anamnesis and clinical signs and can be verified by the detection of elevated creatine kinase activity, specific profile of acylcarnitines and the presence of HGA, MCPrG conjugates and/or their metabolites in peripheral blood and/or urine. Dry blood spots were collected for 15 days from a 3.5-year-old stallion which had been affected by AM and, as a control group, from twelve healthy horses. Two mass spectrometry methods were used for the analysis of 31 acylcarnitines, carnitine, HGA, MCPrG and their metabolites. HGA and six increased acylcarnitines were detected in the patient’s blood throughout the monitoring period. Nine acylcarnitines were strongly correlated with HGA. Multivariate statistical analysis showed a clear separation of samples from the AM horse, where the metabolic profile tended to normalization in the later days after intoxication. Due to the longer persistence in the blood, the detection of HGA and elevated acylcarnitines profile appear to be an appropriate tool to confirm the diagnosis of AM, compared to metabolic products of HGA and MCPrG even in advanced cases.
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Affiliation(s)
- Petr Jahn
- Equine Clinic, Faculty of Veterinary Medicine, University of Veterinary Sciences, Brno, Czech Republic
| | - Dana Dobešová
- Laboratory for Inherited Metabolic Disorders, Department of Clinical Biochemistry, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacký University Olomouc, Czech Republic
| | - Radana Brumarová
- Laboratory for Inherited Metabolic Disorders, Department of Clinical Biochemistry, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacký University Olomouc, Czech Republic
| | - Katarína Tóthová
- Equine Clinic, Faculty of Veterinary Medicine, University of Veterinary Sciences, Brno, Czech Republic
| | - Andrea Kopecká
- Equine Clinic, Faculty of Veterinary Medicine, University of Veterinary Sciences, Brno, Czech Republic
| | - David Friedecký
- Laboratory for Inherited Metabolic Disorders, Department of Clinical Biochemistry, University Hospital Olomouc and Faculty of Medicine and Dentistry, Palacký University Olomouc, Czech Republic
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González-Medina S, Montesso F, Chang YM, Hyde C, Piercy RJ. Atypical myopathy-associated hypoglycin A toxin remains in sycamore seedlings despite mowing, herbicidal spraying or storage in hay and silage. Equine Vet J 2019; 51:701-704. [PMID: 30629759 DOI: 10.1111/evj.13070] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 12/30/2018] [Indexed: 11/27/2022]
Abstract
BACKGROUND Several pasture management strategies have been proposed to avoid hypoglycin A (HGA) intoxication in horses, but their efficacy has never been investigated. OBJECTIVES To evaluate the effect of mowing and herbicidal spraying on HGA content of sycamore seedlings and the presence of HGA in seeds and seedlings processed within haylage and silage. STUDY DESIGN Experimental study. METHODS Groups of seedlings were mowed (n = 6), sprayed with a dimethylamine-based (n = 2) or a picolinic acid-based herbicide (n = 1). Seedlings were collected before intervention, and at 48 h, 1 and 2 weeks after. Cut grass in the vicinity of mowed seedlings was collected pre-cutting and after 1 week. Seeds and seedling (n = 6) samples processed within haylage and silage were collected. HGA concentration in samples was measured using a validated LC-MS-based method. RESULTS There was no significant decline in HGA content in either mowed or sprayed seedlings; indeed, mowing induced a temporary significant rise in HGA content of seedlings. HGA concentration increased significantly (albeit to low levels) in grass cut with the seedlings by 1 week. HGA was still present in sycamore material after 6-8 months storage within either hay or silage. MAIN LIMITATIONS Restricted number of herbicide compounds tested. CONCLUSIONS Neither mowing nor herbicidal spraying reduces HGA concentration in sycamore seedlings up to 2 weeks after intervention. Cross contamination is possible between grass and sycamore seedlings when mowed together. Mowing followed by collection of sycamore seedlings seems the current best option to avoid HGA toxicity in horses grazing contaminated pasture. Pastures contaminated with sycamore material should not be used to produce processed hay or silage as both seedlings and seeds present in the bales still pose a risk of intoxication.
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Affiliation(s)
- S González-Medina
- Comparative Neuromuscular Diseases Laboratory, Royal Veterinary College, University of London, London, UK
| | - F Montesso
- Centre for Preventive Medicine, Animal Health Trust, Newmarket, Suffolk, UK
| | - Y-M Chang
- Comparative Neuromuscular Diseases Laboratory, Royal Veterinary College, University of London, London, UK
| | - C Hyde
- Bio-Analysis Centre, London, UK
| | - R J Piercy
- Comparative Neuromuscular Diseases Laboratory, Royal Veterinary College, University of London, London, UK
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González-Medina S, Ireland JL, Piercy RJ, Newton JR, Votion DM. Equine atypical myopathy in the UK: Epidemiological characteristics of cases reported from 2011 to 2015 and factors associated with survival. Equine Vet J 2017; 49:746-752. [PMID: 28445006 DOI: 10.1111/evj.12694] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Accepted: 04/16/2017] [Indexed: 11/30/2022]
Abstract
BACKGROUND Equine atypical myopathy (AM) is a toxic rhabdomyolysis associated with ingestion of hypoglycin A, derived typically in Europe, from Acer pseudoplatanus tree. Despite the wide distribution of this tree species in the UK, the number of cases reported annually varies, and there has been an apparent increase in prevalence in recent years. Although AM was first recognised in the UK, epidemiological studies have never been conducted focused solely on this country. OBJECTIVES To describe the spatiotemporal distribution, presentation, treatment and outcome of AM cases reported in the UK. STUDY DESIGN Retrospective case series. METHODS British AM cases reported to the atypical myopathy alert website, between 2011 and 2015 were included (n = 224). Data were obtained via standardised epidemiological questionnaires from owners and veterinarians. Factors associated with survival were assessed using logistic regression. RESULTS Most cases reported were from England (87.9%). Survival was 38.6% (n = 73/189). Clinical factors associated with reduced odds of survival included, hypothermia (odds ratio [OR] 0.18; 95% confidence interval [CI] 0.06-0.57; P = 0.01), bladder distension (OR 0.11; CI 0.02-0.59; P = 0.01), tachycardia (OR 0.97; CI 0.94-0.99; P = 0.04) and serum creatine kinase activity >100,000 IU/L (OR 0.17; CI 0.04-0.68; P = 0.01) in the univariable analysis as well as recumbency. The latter was the only sign retained in multivariable analysis (OR = 0.19; CI 0.06-0.62; P = 0.006). Administration of vitamins during the disease was associated with survival (OR 3.75; CI 1.21-11.57; P = 0.02). MAIN LIMITATIONS Reporting cases to the Atypical Myopathy Alert Group is voluntary; therefore, under-reporting will result in underestimation of AM cases; furthermore, direct owner-reporting could have introduced misdiagnosis bias. CONCLUSION Some areas of the UK reported AM cases more commonly. Clinical signs such as recumbency, rectal temperature, distended bladder and serum creatine kinase activity might be useful prognostic indicators though should be considered in the context of the clinical picture. Treatment with vitamins increases odds of survival.
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Affiliation(s)
- S González-Medina
- Comparative Neuromuscular Diseases Laboratory, The Royal Veterinary College, London, UK.,Epidemiology and Disease Surveillance, Animal Health Trust, Newmarket, Suffolk, UK
| | - J L Ireland
- Epidemiology and Disease Surveillance, Animal Health Trust, Newmarket, Suffolk, UK
| | - R J Piercy
- Comparative Neuromuscular Diseases Laboratory, The Royal Veterinary College, London, UK
| | - J R Newton
- Epidemiology and Disease Surveillance, Animal Health Trust, Newmarket, Suffolk, UK
| | - D M Votion
- Equine Medicine Department, Pole Equine, Faculty of Veterinary Medicine, University of Liège, Liège, Belgium
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Westermann CM, van Leeuwen R, van Raamsdonk LWD, Mol HGJ. Hypoglycin A Concentrations in Maple Tree Species in the Netherlands and the Occurrence of Atypical Myopathy in Horses. J Vet Intern Med 2016; 30:880-4. [PMID: 26995161 PMCID: PMC4913566 DOI: 10.1111/jvim.13927] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 01/15/2016] [Accepted: 02/18/2016] [Indexed: 11/28/2022] Open
Abstract
Background Atypical myopathy (AM) in horses is caused by the plant toxin hypoglycin A, which in Europe typically is found in the sycamore maple tree (Acer pseudoplatanus). Owners are concerned about whether their horses are in danger if they graze near maple trees. Hypothesis/Objectives To measure hypoglycin A in the most common maple tree species in the Netherlands, and to determine whether concentration of toxin is a predictor of AM in horses. Methods A total of 278 samples of maple tree leaves, sprouts, and seeds were classified by species. Mean concentrations of hypoglycin A were compared for the type of sample, the season and the occurrence of AM in the pasture (non‐AM versus AM). Statistical analysis was performed using generalized a linear model (SPPS22). Results Almost all Acer pseudoplatanus samples contained hypoglycin A, with concentrations differing significantly among sources (P < .001). Concentrations were significantly higher in seeds from the AM group than in seeds from the non‐AM group (856 ± 677 and 456 ± 358 mg/kg, respectively; P = .039). In sprouts and leaves this was not the case. Acer platanoides and Acer campestre samples did not contain detectable concentrations of hypoglycin A. Conclusions and clinical importance Acer platanoides and campestre seem to be safe around paddocks and pastures, whereas almost all Acer pseudoplatanus samples contained hypoglycin A. In all AM cases, Acer pseudoplatanus was found. Despite significantly higher concentration of hypoglycin A in seeds of pastures where AM has occurred, individual prediction of AM cannot be made by measuring these concentrations because of the high standard deviation.
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Affiliation(s)
- C M Westermann
- Department of Equine Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, the Netherlands
| | | | | | - H G J Mol
- RIKILT-Wageningen UR, Wageningen, the Netherlands
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Baise E, Habyarimana JA, Amory H, Boemer F, Douny C, Gustin P, Marcillaud-Pitel C, Patarin F, Weber M, Votion DM. Samaras and seedlings of Acer pseudoplatanus are potential sources of hypoglycin A intoxication in atypical myopathy without necessarily inducing clinical signs. Equine Vet J 2015; 48:414-7. [PMID: 26278545 DOI: 10.1111/evj.12499] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 08/07/2015] [Indexed: 11/28/2022]
Abstract
REASONS FOR PERFORMING STUDY Ingestion of sycamore seeds (Acer pseudoplatanus) is the likely source of hypoglycin A in atypical myopathy (AM) but ingestion of seedlings in spring might also contribute to intoxication. OBJECTIVES To test for hypoglycin A in seeds and seedlings collected on pastures where AM cases were reported and compare its concentration in serum of affected and healthy horses. STUDY DESIGN Field investigation of clinical cases. METHODS Whenever present, samaras (the winged nuts that each contain one seed) and/or seedlings were collected from pastures of 8 AM cases and 5 unaffected horses from different premises. Two AM cases were each co-grazing with an apparently healthy horse. Acylcarnitines and hypoglycin A were quantified in blood samples of all horses involved in the study. RESULTS Hypoglycin A was detected in serum of AM (5.47 ± 1.60 μmol/l) but not in healthy controls pasturing where A. pseudoplatanus trees were not present. However, hypoglycin A was detected at high concentrations (7.98 μmol/l) in serum of a clinically healthy horse grazing a pasture with seedlings and samaras and also in the 2 healthy horses co-grazing with AM cases (0.43 ± 0.59 μmol/l). Hypoglycin A was detected in all samples of seeds and spring seedlings of A. pseudoplatanus. CONCLUSIONS Atypical myopathy can be associated with the ingestion of sycamore samaras and also ingestion of seedlings. Hypoglycin A can be detected in the blood of horses with no detectable clinical signs at pasture in which there is A. pseudoplatanus. Determination of hypoglycin A concentration in blood is useful for screening for exposure in suspected cases of AM.
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Affiliation(s)
- E Baise
- Department of Animal Productions: Biostatistics, Economy and Animal Selection, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium
| | - J A Habyarimana
- Department of Functional Sciences, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium
| | - H Amory
- Equine Pole, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium
| | - F Boemer
- Biochemical Genetics Laboratory, CHU Sart-Tilman, University of Liege, Belgium
| | - C Douny
- Department of Food Sciences, Laboratory of Food Analysis, Fundamental and Applied Research for Animals and Health (FARAH) - Veterinary Public Health, University of Liège, Belgium
| | - P Gustin
- Department of Functional Sciences, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium
| | - C Marcillaud-Pitel
- Réseau d'EpidémioSurveillance en Pathologie Equine (RESPE), Caen, France
| | - F Patarin
- Equine Pole, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium
| | - M Weber
- Department of Functional Sciences, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium
| | - D-M Votion
- Equine Pole, Fundamental and Applied Research for Animals and Health (FARAH), Faculty of Veterinary Medicine, University of Liege, Belgium
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McKenzie RK, Gibson IR, Ritmeester A. Three cases of a presumptive atypical myopathy in New Zealand horses. N Z Vet J 2013; 61:367-72. [DOI: 10.1080/00480169.2013.796436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Votion DM, van Galen G, Sweetman L, Boemer F, de Tullio P, Dopagne C, Lefère L, Mouithys-Mickalad A, Patarin F, Rouxhet S, van Loon G, Serteyn D, Sponseller BT, Valberg SJ. Identification of methylenecyclopropyl acetic acid in serum of European horses with atypical myopathy. Equine Vet J 2013; 46:146-9. [PMID: 23773055 DOI: 10.1111/evj.12117] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 06/09/2013] [Indexed: 11/27/2022]
Abstract
REASONS FOR PERFORMING STUDY It is hypothesised that European atypical myopathy (AM) has a similar basis as seasonal pasture myopathy in North America, which is now known to be caused by ingestion of hypoglycin A contained in seeds from the tree Acer negundo. Serum from horses with seasonal pasture myopathy contained the conjugated toxic metabolite of hypoglycin A, methylenecyclopropyl acetic acid (MCPA). STUDY DESIGN Retrospective study on archived samples. OBJECTIVES 1) To determine whether MCPA-carnitine was present in serum of European horses confirmed to have AM; 2) to determine whether Acer negundo or related Acer species were present on AM pastures in Europe. METHODS Concentrations of MCPA-carnitine were analysed in banked serum samples of 17 AM horses from Europe and 3 diseased controls (tetanus, neoplasia and exertional rhabdomyolysis) using tandem mass spectrometry. Atypical myopathy was diagnosed by characteristic serum acylcarnitine profiles. Pastures of 12 AM farms were visited by experienced botanists and plant species were documented. RESULTS Methylenecyclopropyl acetic acid-carnitine at high concentrations (20.39 ± 17.24 nmol/l; range 0.95-57.63 nmol/l; reference: <0.01 nmol/l) was identified in serum of AM but not disease controls (0.00 ± 0.00 nmol/l). Acer pseudoplatanus but not Acer negundo was present on all AM farms. CONCLUSIONS Atypical myopathy in Europe, like seasonal pasture myopathy in North America, is highly associated with the toxic metabolite of hypoglycin A, MCPA-carnitine. This finding coupled with the presence of a tree of which seeds are known to also contain hypoglycin A indicates that ingestion of Acer pseudoplatanus is the probable cause of AM. This finding has major implications for the prevention of AM.
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Affiliation(s)
- D-M Votion
- Equine Clinic, Faculty of Veterinary Medicine, University of Liege, Belgium
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van Galen G, Cerri S, Porter S, Saegerman C, Lefere L, Roscher K, Marr C, Amory H, Votion DM. Traditional and quantitative assessment of acid-base and shock variables in horses with atypical myopathy. J Vet Intern Med 2012. [PMID: 23193982 DOI: 10.1111/jvim.12003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND Descriptions of acid-base disturbances in atypical myopathy (AM) are limited. OBJECTIVES Describe and compare traditional and quantitative acid-base abnormalities and cardiovascular shock status in horses with AM at admission. ANIMALS 34 horses with AM, 15 healthy controls. METHODS Retrospective case-control study. Records were searched for shock variables (packed cell volume [PCV], blood urea nitrogen [BUN], heart and respiratory rate) and acid-base variables (venous blood gas analysis, electrolytes, total protein, lactate) on admission. Base excess (BE) of free water (BEfw), chloride (BEcl), total protein (BEtp), and unidentified anions (BEua), anion gap (AG), measured strong ion difference (SIDm), and concentration of total nonvolatile weak acids ([Atot]) were calculated. Acid-base classifications, using simplified strong ion model and traditional approach, and shock grades were assigned. A 2-sample Wilcoxon rank-sum test and Bonferroni correction compared variables in AM cases versus control horses. Significance was P < .05/16 for acid-base and P < .05/5 for shock variables. RESULTS Tachycardia, tachypnea, and normal to increased PCV and BUN were common in AM cases. Respiratory, metabolic acid-base alterations, or both were mainly caused by respiratory alkalosis, lactic acidosis, and SIDm alkalosis, alone or in combination. Evaluated variables (except pH, potassium concentration, total protein, and related calculations) were significantly different (P < .001) between AM cases and control horses. The strong ion model provided a more accurate assessment than the traditional approach and identified mixed derangements. CONCLUSIONS AND CLINICAL IMPORTANCE Acid-base derangements should be evaluated in horses with AM and this preferably with the strong ion model.
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Affiliation(s)
- G van Galen
- Department of Epidemiology, Unité de recherche en epidémiologie et analyse de risques appliquées aux sciences vétérinaires, FMV University of Liege, Belgium.
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Votion DM. The story of equine atypical myopathy: a review from the beginning to a possible end. ISRN VETERINARY SCIENCE 2012; 2012:281018. [PMID: 23762581 PMCID: PMC3671727 DOI: 10.5402/2012/281018] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Accepted: 09/25/2012] [Indexed: 11/23/2022]
Abstract
Atypical myopathy (AM) is a frequently fatal seasonal pasture myopathy that emerges in Europe. Outbreaks are of an acute and unexpected nature and practitioners should be prepared to handle these critically ill patients. This review retraces the history of AM and describes results of epidemiological investigations that were conducted to raise hypotheses concerning the etiology of this devastating disease as well as to be able to suggest potential preventive measures. Also, clinical studies have contributed to a better definition and recognition of the syndrome, whereas elucidation of the pathological process, identified as a multiple acyl-CoA dehydrogenase deficiency (MADD), was a great step forward improving medical management of AM and guiding the search for the etiological agent towards toxins that reproduce the identified defect. Treatment plans can be extrapolated from the described clinical signs and metabolic problems, but they remain limited to supportive care until the causative agent has been identified with certainty. Since treatment is still unsuccessful in the majority of cases, the main emphasis is currently still on prevention. This paper aims at being a practical support for equine clinicians dealing with AM and is based on discussion and comparison of the currently available scientific data.
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Affiliation(s)
- Dominique-Marie Votion
- Equine Clinic, Faculty of Veterinary Medicine, University of Liege, Boulevard de Colonster 20 B41, 4000 Liege, Belgium
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van Galen G, Votion DM. Management of cases suffering from atypical myopathy: Interpretations of descriptive, epidemiological and pathophysiological findings. Part 2: Muscular, urinary, respiratory and hepatic care, and inflammatory/infectious status. EQUINE VET EDUC 2012. [DOI: 10.1111/j.2042-3292.2012.00441.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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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] [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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van Galen G, Saegerman C, Marcillaud Pitel C, Patarin F, Amory H, Baily JD, Cassart D, Gerber V, Hahn C, Harris P, Keen JA, Kirschvink N, Lefere L, McGorum B, Muller JMV, Picavet MTJE, Piercy RJ, Roscher K, Serteyn D, Unger L, van der Kolk JH, van Loon G, Verwilghen D, Westermann CM, Votion DM. European outbreaks of atypical myopathy in grazing horses (2006-2009): determination of indicators for risk and prognostic factors. Equine Vet J 2012; 44:621-5. [PMID: 22413891 DOI: 10.1111/j.2042-3306.2012.00555.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
REASONS FOR PERFORMING STUDY Appropriate management of atypical myopathy (AM) requires the establishment of an accurate diagnosis and prognosis. Furthermore, preventive measures to avoid AM need to be refined. OBJECTIVES The aims of the study were as follows: 1) to improve the diagnosis of AM; 2) to identify prognostic predictors; and 3) to refine recommended preventive measures based on indicators of risk factors. METHODS An exploratory analysis of cases in Europe between 2006 and 2009 reported to the Atypical Myopathy Alert Group was conducted. Based on clinical data, reported cases were allocated into 2 groups: confirmed or highly probable AM (AM group; further divided into survivors and nonsurvivors); and cases with a low probability of having AM or with another final diagnosis (non-AM group). Using Welch's test and odds ratios corrected for multiple comparisons, the AM vs. non-AM groups were compared to identify indicators for diagnosis and risk factors, and survivors vs. nonsurvivors in the AM group were compared to identify prognostic factors. Sensitivity, specificity and positive and negative predictive values were calculated for specific clinical signs related to final diagnosis and outcome. RESULTS From 600 reported cases, 354 AM cases (survival rate of 26%) and 69 non-AM cases were identified, while there were insufficient data to categorise the remainder. Variables valuable for diagnosing AM compared with similar diseases were as follows: presence of dead leaves and wood and/or trees on pastures; sloping pastures; full-time pasture access; no food supplementation; normal body condition; pigmenturia; normothermia; and congested mucous membranes. Nonsurvival was associated with recumbency, sweating, anorexia, dyspnoea, tachypnoea and/or tachycardia. Survival was associated with remaining standing most of the time, normothermia, normal mucous membranes, defaecation and vitamin and antioxidant therapy. CONCLUSIONS AND POTENTIAL RELEVANCE This study refines the list of risk factors for AM. Clinical signs valuable for diagnosis and prognosis have been identified, enabling clinicians to improve management of AM cases.
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Affiliation(s)
- G van Galen
- Department of Epidemiology, Faculty of Veterinary Medicine, University of Liege, Belgium.
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