Severe polysaccharide storage myopathy in Belgian and Percheron draught horses.
Abstract: A severe myopathy leading to death or euthanasia was identified in 4 Belgian and 4 Percheron draught horses age 2-21 years. Clinical signs ranged from overt weakness and muscle atrophy in 2 horses age 2 and 3 years, to recumbency with inability to rise in 6 horses age 4-21 years. In 5 horses there was mild to severe increases in muscle enzyme levels. Clinical diagnoses included equine motor neuron disease (2 horses), post anaesthetic myopathy (2 horses), exertional myopathy (2 horses), myopathy due to unknown (one horse), and equine protozoal myelitis (one horse). Characteristic histopathology of muscle from affected horses was the presence of excessive complex polysaccharide and/or glycogen, revealed by periodic acid-Schiff staining in all cases and by electron microscopy in one case. Evaluation of frozen section histochemistry performed on 2 cases indicated that affected fibres were Type 2 glycolytic fibres. Subsarcolemmal and intracytoplasmic vacuoles were most prominent in 3 horses age 2-4 years, and excessive glycogen, with little or no complex polysaccharide, was the primary compound stored in affected muscle in these young horses. Myopathic changes, including fibre size variation, fibre hypertrophy, internal nuclei, and interstitial fat infiltration, were most prominent in 5 horses age 6-21 years, and the accumulation of complex polysaccharide appeared to increase with age. Mild to moderate segmental myofibre necrosis was present in all cases.
Publication Date: 1997-05-01 PubMed ID: 9234015DOI: 10.1111/j.2042-3306.1997.tb01672.xGoogle Scholar: Lookup
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- Case Reports
- Journal Article
- Research Support
- Non-U.S. Gov't
- Age Factors
- Case Reports
- Clinical Pathology
- Clinical Signs
- Diagnosis
- Disease Diagnosis
- Draft Horses
- Equine Diseases
- Equine Health
- Equine Motor Neuron Disease
- Equine Protozoal Myeloencephalitis
- Glycogen
- Glycolysis
- Histopathology
- Horses
- Muscle
- Muscle Fiber Types
- Necrosis
- Polysaccharide Storage Myopathy
- Veterinary Medicine
Summary
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This research investigates a severe myopathic condition in 4 Belgian and 4 Percheron draught horses aged between 2 to 21 years. The condition leads to severe muscular symptoms and even death or euthanasia. The deterioration of the muscle cells is linked with accumulation of excessive complex polysaccharides and/or glycogen, particularly affecting Type 2 glycolytic fibres.
Subjects and Diagnosis
- This research studies eight draught horses – 4 Belgian and 4 Percheron – ranging in age from 2 to 21 years.
- All horses presented with clinical signs such as overt weakness or muscle atrophy, or recumbency with an inability to rise.
- Various health conditions including equine motor neuron disease, post anaesthetic myopathy, exertional myopathy, myopathy of unknown source and equine protozoal myelitis were initially suggested as the cause behind these symptoms.
Results and Histopathology
- Through muscle biopsy and staining methods like periodic acid-Schiff staining, it was observed that muscle cells from these horses contained excessive quantities of complex polysaccharides and/or glycogen.
- Electron microscopy performed on one horse confirmed the presence of these compounds.
- On further investigation, Type 2 glycolytic fibres were identified as the affected fibres.
- Younger horses aged between 2 to 4 years exhibited prominent subsarcolemmal and intracytoplasmic vacuoles along with an abundance of glycogen, but little or no complex polysaccharides in the muscle tissue.
Myopathic Changes and Pattern
- Myopathic changes, such as variations in fibre size, fibre hypertrophy, internal nuclei, and interstitial fat infiltration were primarily observed in older horses between the ages of 6 to 21 years.
- The accumulation of complex polysaccharides appeared to increase with the age of the horses.
- Symptoms of segmental myofibre necrosis, or the death of sections of muscle fibres, were present in all cases, indicating severe muscle damage.
Cite This Article
APA
Valentine BA, Credille KM, Lavoie JP, Fatone S, Guard C, Cummings JF, Cooper BJ.
(1997).
Severe polysaccharide storage myopathy in Belgian and Percheron draught horses.
Equine Vet J, 29(3), 220-225.
https://doi.org/10.1111/j.2042-3306.1997.tb01672.x Publication
Researcher Affiliations
- Department of Pathology, College of Veterinary Medicine, Cornell University, Ithaca, New York 14853, USA.
MeSH Terms
- Animals
- Atrophy
- Female
- Glycogen / metabolism
- Glycogen Storage Disease / complications
- Glycogen Storage Disease / metabolism
- Glycogen Storage Disease / pathology
- Glycogen Storage Disease / veterinary
- Histocytochemistry
- Horse Diseases / metabolism
- Horse Diseases / pathology
- Horses
- Hypertrophy
- Male
- Microscopy, Electron, Scanning Transmission
- Muscle Fibers, Skeletal / pathology
- Muscle, Skeletal / metabolism
- Muscle, Skeletal / pathology
- Muscular Diseases / etiology
- Muscular Diseases / metabolism
- Muscular Diseases / pathology
- Muscular Diseases / veterinary
- Necrosis
- Polysaccharides / metabolism
Citations
This article has been cited 2 times.- Sprayberry KA, Madigan J, LeCouteur RA, Valentine BA. Renal failure, laminitis, and colitis following severe rhabdomyolysis in a draft horse-cross with polysaccharide storage myopathy. Can Vet J 1998 Aug;39(8):500-3.
- Lindsay-McGee V, Massey C, Li YT, Clark EL, Psifidi A, Piercy RJ. Characterisation of phenotypic patterns in equine exercise-associated myopathies. Equine Vet J 2025 Mar;57(2):347-361.
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