title: An epidemiological study of myopathies in Warmblood horses.
abstract: BACKGROUND
  There are few detailed reports describing muscular disorders in Warmblood horses.
  
  
  OBJECTIVE
  To determine the types of muscular disorders that occur in Warmblood horses, along with presenting clinical signs, associated risk factors and response to diet and exercise recommendations, and to compare these characteristics between horses diagnosed with polysaccharide storage myopathy (PSSM), those diagnosed with a neuromuscular disorder other than PSSM (non-PSSM) and control horses.
  
  
  METHODS
  Subject details, muscle biopsy diagnosis and clinical history were compiled for Warmblood horses identified from records of biopsy submissions to the University of Minnesota Neuromuscular Diagnostic Laboratory. A standardised questionnaire was answered by owners at least 6 months after receiving the muscle biopsy report for an affected and a control horse.
  
  
  RESULTS
  Polysaccharide storage myopathy (72/132 horses) was the most common myopathy identified followed by recurrent exertional rhabdomyolysis (RER) (7/132), neurogenic or myogenic atrophy (7/132), and nonspecific myopathic changes (14/132). Thirty-two biopsies were normal. Gait abnormality, 'tying-up', Shivers, muscle fasciculations and atrophy were common presenting clinical signs. Forty-five owners completed questionnaires. There were no differences in sex, age, breed, history or management between control, PSSM and non-PSSM horses. Owners that provided the recommended low starch fat supplemented diet and regular daily exercise reported improvement in clinical signs in 68% (19/28) of horses with a biopsy submission and 71% of horses diagnosed with PSSM (15/21).
  
  
  CONCLUSIONS
  Muscle biopsy evaluation was a valuable tool to identify a variety of myopathies in Warmblood breeds including PSSM and RER. These myopathies often presented as gait abnormalities or overt exertional rhabdomyolysis and both a low starch fat supplemented diet and regular exercise appeared to be important in their successful management.
  
  
  CONCLUSIONS
  Warmbloods are affected by a variety of muscle disorders, which, following muscle biopsy diagnosis can be improved through changes in diet and exercise regimes.
authors: Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota, 1365 Gortner Avenue, St Paul, Minnesota 55108, USA.
authors: L M
authors: LM
authors: Hunt
authors: S J
authors: SJ
authors: Valberg
authors: K
authors: K
authors: Steffenhagen
authors: M E
authors: ME
authors: McCue
mesh_terms: D000818:Animals; D001706:Biopsy / Q000662:veterinary; D003937:Diagnosis, Differential; D005260:Female; D005500:Follow-Up Studies; D006008:Glycogen Storage Disease / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy / Q000662:veterinary*; D006734:Horse Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000628:therapy; D006736:Horses; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology; D009133:Muscular Atrophy / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy / Q000662:veterinary*; D009135:Muscular Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy / Q000662:veterinary*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012189:Retrospective Studies; D012206:Rhabdomyolysis / Q000175:diagnosis / Q000453:epidemiology / Q000628:therapy / Q000662:veterinary*; D012307:Risk Factors; D013213:Starch / Q000008:administration & dosage* / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D013213:Starch