Domestic cat calcium levels low. A reason.

When a domestic cat is suffering from a deficiency in calcium i.e. their blood-calcium concentration is low, it may well be due to inadvertent damage to the parathyroid glands during a thyroidectomy operation. This is an operation to remove the thyroid gland because the cat is suffering from hyperthyroidism. A dramatic fall in blood-calcium concentrations can be life-threatening. Cats who have been through the thyroidectomy operation should be hospitalised for a few days after surgery so the blood-calcium concentrations can be monitored.

Thin, elderly cat suffering from hyperthyroidism. Picture: PoC.

Hyperthyroidism is fairly common in older cats and is caused by an increase in the production of thyroid hormones from enlarged thyroid glands in the cat's neck. Most often it is caused by a benign tumour hence the operation. It should be noted that second hand cigarette smoke may be a contributory factor in developing this disease. Surgery is an option to remove the cancerous gland. If both thyroid glands are removed the cat will need supplemental thyroid for the remainder of their life.

Alternative options are radioactive iodine to destroy the cancerous tissue or an oral medication called methimazole. This drug lowers hormone production. It is given daily. The administration of this drug can it seems be difficult but the manufacturers are making it more palatable. Perhaps they have done this because my information comes from a book written in 2008.

If hyperthyroidism is caught early before the heart and kidneys are damaged it is a treatable disease. However, if these organs are damaged they will need treatment after the thyroidectomy. A thyroidectomy is a straightforward operation with an excellent success rate but beware the parathyroid glands!

Diagnosis for hyperthyroidism is carried out by a vet examining the cat's neck area for enlarged glands and they check the heart rate and blood pressure. The cat's general health is also evaluated because hyperthyroidism is often associated with other conditions and it can predispose a cat to other conditions. Therefore they need to be checked for associated conditions.

P.S. Other potential reasons for low blood calcium in cats might be kidney or liver failure, parathyroid tumour, hypoparathyroidism or poor nutrition during pregnancy to name some examples. I'm not a veterinarian so I won't go on.

Sources: Dr Bruce Fogle, Drs Eldredge, Carlson, Carlson and Giffin.