Species Specific Muscle and Tendon Lesions Flashcards
What muscle diseases do dogs get?
eosinophilic myositis, neosporosis, and Myasthenia gravis
What does eosinophilic myositis effect?
the muscles of mastication
What can eosinophilic myositis progress to?
atrophic myositis
What is eosinophilic myositis?
an autoimmune disease targeting type 2M myocytes
What causes neosporosis?
Neospora caninum
What is neosporosis acquired by?
ingesting infected tissue (aborted calves)
What does neosporosis cause?
necropurulent myositis
What is Myasthenia gravis?
muscle weakness
What causes myasthania gravis?
a decrease of ACH receptors at the myoneural junction (can be either inherited or acquired)
What specific gross/microscopic lesions can myasthenia gravis cause?
no specific gross/microscopic lesions +/- megaesophagous
What skeletal muscle diseases do equine get?
exertional myopathy, equine polysaccharide storage myopathy, hyperkalemic periodic paralysis, nutritional myopathy, ionophore toxicosis, lower motor neuron disease, clostridial myositis
What is another name for exertional myopathy?
equine rhabdomyolysis
What is equine rhabdomyolysis associated with?
high grain ration followed by muscle use in draft horses
What forms of exertional myopathy are there?
sporadic or recurrent
What is equine rhabdomyolysis considered to be due to?
underlying metabolic abnormaity
What does exertional myopathy cause?
acute myodegeneration which leads to myoglobinuria and increased creatine phosphokinase
What is equine polysaccharide storage myopathy?
the accumulation of polysacchawride aggregates in type 2 myocytes
What can repeated bouts of myodegeneration due to equine polysaccharide storage myopathy result in?
muscle atrophy
What causes hyperkalemic periodic paralysis?
an autosomal dominant trait in quarter horses that is acquired from ‘impressive’
What is the ‘pathogenesis’ of hyperkalemic periodic paralysis?
defective Na channel regulation in myocytes which leads to polarization abnormalities and eventually causes myotonia with or without hyperkalemia
What is nutritional myopathy in horses?
it is vitamin E/Se deficiency in foals
What clinical signs/lesions does nutritional myopathy cause in horses?
swollen, pale muscles with polyphasic myodegeneration
What ionophore primarily causes ionophore toxicosis?
monensin
What does ionophore toxicosis cause?
acute myodegeneration and necrosis
What is lower motor neuron disease in horses?
lower motor neuron loss which leads to denervation of atrophy of muscles
What can lower motor neuron disease be due to?
vitamin E/Se deficiency
What causes clostridial myositis?
wound infection with clostridia sp.
What does clostridial myositis cause?
serohemorrhagic exudate, necrosis, muscle emphysema, and malignant edema
What skeletal muscle diseases do pigs get?
nutritional myopathy and malignant hyperthermia
What causes nutritional myopathy in pigs?
vitamin E/Se deficiency
What does nutritional myopathy in pigs cause?
lesions in skeletal muscle and or the myocardium
What is malignant hyperthermia in pigs?
an inherited defect in the Ca channel regulation between T-tubule and SR which leads to Ca release into the sarcoplasm and myofiber contraction
What does malignant hyperthermia in pigs cause?
acute myodegeneration
What skeletal muscle diseases do ruminants get?
nutritional myopathy and clostridial myositis
What causes nutritional myopathy in ruminants?
vitamin E/Se deficiency
What does does nutritional myopathy in ruminants cause and in which specific populations?
lesions in skeletal muscle in calves and lambs
What causes clostridial myositis (black leg) in ruminants?
Clostridia chauvoei
What does clostridial myositis in cows cause?
acute necrohemorrhagic myositis with muscle emphysema
What is the pathogenesis of clostridial myositis in ruminants?
bruising to anaerobic focus to germination of spores to tissue destruction due to bacterial toxins
