8 Myopathies associated with serum electrolyte imbalance

8.1 Feline hypokalemia

Hypokalemia in cats can lead to a distinct clinical syndrome called feline hypokalemic polymyopathy. It is characterized by ventroflexion of the neck, a stiff, stilted gait, muscle pain, reluctance to walk, and weakness. Low potassium can be the result of decreased dietary intake, chronic renal disease, or in cats fed acidifying diets to control urolithiasis. The pathogenesis of muscle injury in hypokalemia is attributed to a decrease in resting membrane potential of myofibers, atlerted glycogen metabolism, and ischemia from hypokalemia-induced vasocontriction. Frustratingly, lesions can be mild or absent in clinical cases. Histologic lesions are most likely to be found in respiratory muscles – the intercostals and the diaphram – and these are recommended for sampling at autopsy if the disease is suspected.

8.2 Bovine hypokalemia

Rather specifically, muscle weakness has been observed in cattle being treated with isoflupredone for ketosis. The drug can cause severe hypokalemia. These animals are weak and recumbent. Acute necrosis occurs in both weight- and non-weight bearing muscles.