Hypokalemic Polymyopathy Syndrome – Causes & Treatment

Sudden onset of muscle weakness, an inability to lift the head, a reluctance or inability to stand or walk, and a crouched posture may occur in cats that develop low blood potassium. Such problems characterize Hypokalemic Polymyopathy Syndrome, commonly known as general muscle disease. If treated promptly with potassium (blood potassium should be monitored), affected cats make a full, remarkable recovery. It seems that a small percentage of cats excrete excessive amounts of potassium in the urine and are susceptible to this syndrome. Cat-food manufacturers, especially those producing low magnesium diets are now supplementing their products with extra potassium so that the occurrence of this disease may be avoided.

Causes of Hypokalemic Polymyopathy Syndrome

Low intake of dietary potassium resulting to insufficient potassium levels in certain commercial provisions has been linked to the episodic outbreaks of this disease. In addition, potassium urinary loss may be worsened by some diets. Such diets are acidified to lessen growth of crystalluria and urolithiasis. It has been recommended that a phenomenon peculiar to cats may be represented by augmented potassium loss induced by renal dysfunction. Additionally, chronic potassium exhaustion may pilot progressive renal disease which is associated with increased renal ammoniagenesis, tubulointerstitial injury, renal ischemia and activation of the alternate complement pathway. Also, it may lead to abrupt changes in muscle membrane sodium permeability. Reduced extracellular potassium levels will fabricate an increase in resting membrane potential. It results in a greater difference between resting and threshold potential essential for muscle contraction. This narrowed state of electrical excitability underlies the weakness of muscles. Furthermore, hypokalemia may affect negatively the release of insulin and end-organ sensitivity to insulin. Regarding other causes of hypokalemic polymyopathy syndrome; post-obstructive diuresis following relief of urethral obstruction in cats, include gastrointestinal loss of potassium, administration of loop or thiazide diuretics and mineralocorticoid excess in rare cases may be mentioned.

Clinical Signs of Hypokalemic Polymyopathy Syndrome

Clinical signs of Hypokaelmic Polymyopathy Syndrome include ventroflexion of the neck, muscle pain, generalized weakness, anorexia and abnormal gait. As far as the neurologic examination is concerned, it is normal. Serum chemistries expose hypokalemia (<3.5 mEq/L) and augmented creatinine and CK. The excretion of potassium is increased and the urine has a low specific gravity.

Diagnosis of Hypokalemic Polymyopathy Syndrome

History, clinical signs and measurements of blood potassium levels form the base for diagnosis of hypokalemic polymyopathy syndrome in cats.

Treatment of Hypokalemic Polymyopathy Syndrome

Treatment of Hypokalemic Polymyopathy Syndrome can be done by supplementation of potassium, given PO (5-8 mEq/day). The potassium supplementation is provided by intravenous injections so that the immediate deficit can be corrected. The potassium supplementations by intravenous injections are followed by oral supplementation as long as deemed indispensable. Prognosis for recuperation is good if treatment begins in time. The potassium supplementation may be essentially continued permanently, depending on the cause of occurrence of this disease. Also the alternating monitoring of response to treatment is usually required through analyzing the blood samples in order to ensure the supplementation is enough but not excessive.

The steps to cure the Hypokaelmic Polymyopathy Syndrome must be taken at the earliest onset of the signs or symptoms of this disease. If the condition advances, the respiratory muscles become affected and trouble in breathing might be noted. In relentless cases, death from respiratory paralysis could result. Thus, it is crucial to get this disease cured at the initial stage itself.