Equine Myopathies Flashcards
What are the two main diagnostic techniques for investigating muscle disease?
Muscle enzymes
Muscle biopsy
What are the two main muscle enzymes how long do they take to peak after a muscle insult?
Creatine kinase: peaks at 4-6 hours
AST: peaks at 24 hours
What are the two types of CK and AST sampling?
Single
Dynamic
Why may you see myoglobinuria with myopathies and why is this a problem?
Myoglobin released from muscle cells as they break down
Nephrotoxic
When is myoglobinuria usually seen?
Rhabdomyolysis
What are the two types of muscle biopsy you can take?
Bergstrom needle or open method
For exertional rhabdomyolysis and for equine motor neurone disease, which muscles are used to biopsy?
Exertional rhabdomyolysis - semimembranosus
Equine motor neurone disease - sacrocaudalis dorsalis
What are the main clinical signs of sporadic exertional rhabdomyolysis?
Usually affects hindlimb muscles
Stiff gait
May refuse to move
Muscles may be hard, painful and swollen
What is the cause of sporadic exertional rhabdomyolysis?
Overtraining/overexertion above the level of fitness
How would you treat sporadic exertional rhabdomyolysis?
Rest
NSAIDs
IV fluids
Which breed often sees recurrent exertional rhabdomyolysis and what is it due to?
Thoroughbreds
Due to an abnormality in calcium regulation
How can you prevent recurrent exertional rhabdomyoslysis?
Diet - high fat low starch
Exercise/turn out daily
Dantrolene
What is the aetiology of polysaccharide storage myopathy?
Glycogen storage disorder characterised by increased skeletal muscle glycogen concentration and the accumulation of abnormal amylase resistant polysaccharide in type 2 muscle fibres
What is the main form of prevention/treatment of polysaccharide storage myopathy?
High fat-low starch diet
What are the clinical signs of an atypical myopathy?
Sudden onset muscle weakness and stiffness
Quickly progesses to recumbency and/or death
May show respiratory difficulty
Usually afebrile with normal appetite
