Hypokalemia and Your Cat

What is hypokalemia?
Hypokalemia is a condition where the potassium level in the blood is too low. There are a number of symptoms associated with hypokalemia but the most commonly noticed symptom is muscle weakness or pain, especially weakness of the neck. Other symptoms are less specific and include weight loss, lack of appetite, poor quality hair coat, and lethargy. Some cats with low blood potassium have no obvious signs.

How do cats get hypokalemia?
There are several ways that a cat can become hypokalemic but the most common cause of hypokalemia is chronic renal insufficiency, or chronic renal failure. In this condition, a cat loses excess potassium in the urine, is not able to absorb enough from the stomach and intestines, and frequently is anorexic and so does not take in enough potassium. Feline diets which are high in protein or are used to make urine more acidic (urinary care diets) can make hypokalemia worse.

How is hypokalemia diagnosed?
Hypokalemia is diagnosed from a blood sample. Potassium is measured in the serum portion of the blood. The potassium measured is free potassium which is a very small fraction of the total potassium in a cat's body. Most of the potassium in the body is inside cells and can not be accurately measured. Measurement of serum potassium level is a good but not always completely accurate measure of total body potassium.
If a blood sample indicates that hypokalemia or chronic renal insufficiency is present, appropriate treatment will be recommended. Once treatment is started, a cat's blood potassium must be monitored to make sure it is at a safe level - not too high or too low.

How is hypokalemia treated?
If a cat has very few symptoms or non-life threatening symptoms of hypokalemia, an oral potassium supplement will be prescribed to treat hypokalemia. Cats that are extremely weak and having breathing or heart problems will need to be hospitalized for intravenous potassium supplementation. Cats that do not have symptoms of hypokalemia but may have other symptoms such as vomiting or anorexia may be hospitalized to treat the vomiting and dehydration. Potassium will likely be given intravenously to these cats as well. Once a cat is out of the hospital, oral potassium supplementation will be continued to make sure the blood potassium level remains normal. Follow-ups to test blood potassium as well as other things will be necessary.

My cat's potassium is low but he has no symptoms - should he be treated?
Cats that have hypokalemia but have no symptoms need to be treated with oral potassium supplements. Low potassium contributes to renal damage and may make kidney disease worse.

My cat's potassium is normal but he has chronic renal insufficiency
- should he be treated?
Cats that have blood potassium levels that are in the low half of the normal range should be considered for treatment. Since blood potassium levels are not 100% accurate at measuring total body potassium, a potassium reading in the low half of the normal range can indicate that total body potassium is low in a cat with chronic renal insufficiency. Since preventing hypokalemia and its associated continuing kidney damage is an important part of preserving a cat's quality and length of life, cats with low normal blood potassium may need a supplement. In most instances, any excess oral potassium given to the cat will be eliminated in the urine. It is still very important to have the cat's blood potassium monitored regularly.

Package Insert