Care and Treatment of Hypothyroidism Feline

Hypothyroidism is a disorder of the thyroid gland, a small gland in the neck. Its primary function is to regulate the metabolism. With hypothyroidism, the thyroid is under active, so the metabolism is decreased. Hypothyroidism is rare in cats as opposed to hyperthyroidism (note the er) which is far more common. In fact, hypothyroidism is most likely to occur in a cat who is being treated for hyperthyroidism or after thyroid surgery. The treatment works too well and the thyroid goes from being overactive to being under active. Occasionally hypothyroidism may be seen in older cats, but again, it is rare.

It is interesting to note that hypothyroidism was found to be genetic in a family of Abyssinian cats due to a problem with their ability to metabolize iodine. (A lack of iodine in the diet will cause hypothyroidism, but any commercial cat food has enough iodine in it for your cat’s diet).

In kittens it is a form of dwarfism with enlarged heads and a short neck.

Feline Hypothyroidism Symptoms

Hypothyroidism in cats impacts many parts of the body including the heart and kidneys.

Symptoms in most cats are mild and include:

• Lethargy: lack of interest in play, sleeping more than usual
• Loss of appetite
• Weight gain: even though she may not seem to be eating more than normal (called polyphagia)
• Hair changes: dry and poor condition, thinning hair,
  
• Slow Heartbeat (Bradycardia)
• Hypothermia: below normal body temperature
• Constipation
• Mental dullness

Feline Hypothyroidism Diagnosis

If your cat has symptoms of hypothyroidism, your vet will do some blood tests and feel the thyroid area. In 90% of cases your veterinarian will feel a mass in the thyroid. Blood tests should be done when your cat is otherwise healthy, is not approaching or in a heat cycle, and is not on medication like steroids, non-steroidal anti-inflammatory drugs (NSAIDS), or anti-seizure drugs.

There are several blood tests your vet might do. The common tests look at two thyroid hormones, T3 (triiodothyonine) and T4 (levothyroxine). If your car has hypothyroidism, these hormones will be low.

Hypothyroidism Feline Treatment

Cats with this condition usually benefit from hormone replacement therapy with levothyroxine (the pharmaceutical name for the thyroid hormone thyroxine T4) and a decreased dosage of methimazole (known as the brand Tapazole). Methimazole is used in the treatment of hyperthyroidism to inhibit the synthesis (creation) of thyroid hormones by decreasing iodine use in the thyroid.

You can also discuss natural remedies with your veterinarian that are associated with maintaining healthy thyroid functioning. One product that is made specifically for this purpose for further research is Thyro-Pet.

In general, your cat can survive up to 2 years with the condition.

References Hypothyroidism Feline

The Mechanic’s Guide to Your Patient’s “Idle System:” Thyroid Disease Reviewed
Faunt, K. K.

Diagnostic and Treatment Options for Feline Hyperthyroidism
Richard W. Nelson, DVM, DACVIM
University of California, Davis