Hypokalemia (Low Potassium Levels) in Cats

What is hypokalemia?

Hypokalemia is a term that refers to a low blood concentration of potassium. Potassium is an important electrolyte within the body and is vital for the normal function of muscles and nerves. In some situations, the normal control of body potassium concentration is lost, resulting in depletion of potassium and low blood potassium concentrations.

What are the clinical signs associated with hypokalemia?

Mild to moderate hypokalemia is seen relatively frequently in sick cats, but does not usually cause significant clinical signs. However, if severe hypokalemia develops, it can cause profound and life-threatening clinical signs. The main effect of severe hypokalemia is generalized muscle weakness. Affected cats have difficulty in getting up and walking, and may appear almost "drunk" because of their weakness. A common and characteristic sign of the muscle weakness is the inability to raise their head into a normal position, so that the head is held down or the neck is bent. Hypokalemia can also cause marked depression and lack of appetite. Some cats with hypokalemia may become constipated. In many cases, the cat will have a poor-quality coat.

What causes hypokalemia?

The most common cause of hypokalemia is chronic kidney failure, a condition common in older cats. Severe or chronic vomiting may also cause hypokalemia in cats.

"Hypokalemia is the most common cause
of generalized muscle weakness in cats."

A variety of other diseases can also cause or contribute to hypokalemia (such as hyperthyroidism), but are less common. Hypokalemia is the most common cause of generalized muscle weakness in cats.

How is hypokalemia treated?

Hypokalemia and its associated clinical signs may be quickly corrected by potassium supplementation. In severe cases, potassium may be given intravenously. This rapidly corrects hypokalemia and reverses muscle weakness. Your veterinarian will determine how quickly to correct this deficiency, because if intravenous potassium is given too rapidly, it can cause heart arrhythmias, or abnormal heartbeats. In less severe cases, and for long-term maintenance of blood potassium, dietary supplementation is usually necessary.

The oral supplements, potassium gluconate or potassium citrate, are well tolerated by most cats and are available as a palatable supplement to add to the diet. Depending on the cause, it may be necessary to continue supplementing potassium permanently. Intermittent monitoring of response to treatment is usually necessary through analysis of blood samples, to ensure the supplementation is adequate but not excessive. Excessive potassium levels may also cause problems, primarily with the heart.