Table: Differential Diagnoses of Equine Myopathies - Merck Veterinary Manual

Differential Diagnoses of Equine Myopathies

Differential Diagnoses of Equine Myopathies

*Non-exercise-associated Rhabdomyolysis*
Inflammatory myopathies Clostridial myositis Influenza myositis Sarcocystis myositis Immune-mediated myopathy Nutritional myopathy Vitamin E and selenium deficiency Toxic myopathies Ionophore toxicity Senna occidentalis Pasture myopathies Rayless goldenrod/white snakeroot Hypoglycin A in box elder and European sycamore trees Traumatic myopathies Compressive anesthetic myopathy Trauma Genetic myopathies Glycogen branching enzyme deficiency in Quarter horses Polysaccharide storage myopathy types 1 and 2 Malignant hyperthermia in Quarter horses
*Exertional Rhabdomyolysis*
Focal muscle strain Sporadic tying-up (overexertion) Chronic tying-up Dietary imbalances, vitamins, minerals, electrolytes Polysaccharide storage myopathy types 1 and 2 Malignant hyperthermia Recurrent exertional rhabdomyolysis Idiopathic chronic exertional rhabdomyolysis
*Exertional Myopathy with Normal CK*
Mitochondrial myopathy Polysaccharide storage myopathy type 2
*Muscle Atrophy*
Myogenic atrophy Severe rhabdomyolysis Disuse Cushing disease Immune-mediated myositis (rapid atrophy) Vitamin E–deficient myopathy Homozygous polysaccharide storage myopathy type 1 Polysaccharide storage myopathy type 2 Neurogenic atrophy Equine protozoal myelitis Local nerve trauma Equine motor neuron disease Idiopathic peripheral neuropathy Toxic peripheral neuropathies
*Muscle Fasciculations*
Pain, fear Weakness (botulism, chronic debilitation) Electrolyte abnormalities Equine motor neuron disease Hyperkalemic periodic paralysis Hypokalemia Otobius megnini (ear tick) infestation Myotonic dystrophy Stiff horse syndrome Shivers