Feline Hypothyroidism Symptoms

Feline hypothyroidism is a dysfunction of the thyroid gland, a small gland located in your cat's throat. The thyroid gland regulates your cat's metabolism. In hypothyroidism, the thyroid fails to produce an adequate amount of thyroid hormone, and your cat's metabolic function decreases. This can cause problems with all of your cat's body systems.

Symptoms of Feline Hypothyroidism

Symptoms of hypothyroidism in cats usually include:

  • Lethargy and lack of interest in play
  • Loss of appetite
  • Unexplained weight gain
  • Dry, brittle hair and excessive dandruff; hair loss
  • Slow heart rate
  • Lowered body temperature
  • Constipation
  • Mental dullness
  • Excessive thirst
  • Increased susceptibility to joint disease and ligament damage

Some cats with hypothyroidism may begin to soil indoors or outside of the litter box. Many owners don't realize that failing to use the litter box is often a sign of an underlying medical condition.

Some vets believe that behavior problems may be related to hypothyroidism. Some cats may become more aggressive, begin to suffer from anxiety or develop compulsive behaviors when suffering from hypothyroidism. Middle aged and elderly cats are especially vulnerable to hypothyroidism.

Diagnosing Hypothyroidism in Cats

Hypothyroidism is rare, and often occurs in cats who are undergoing treatment for hyperthyroidism, a condition in which the thyroid gland becomes overactive and produces too much of the thyroid hormone. In these cases, cats develop hypothyroidism because the medications they're receiving work too well, an inhibit thyroid hormone production too much. These cases can be treated simply by adjusting the medication your cat receives.

Your vet will do a blood chemistry panel to determine the levels of thyroid hormone in your cat's blood. If your cat is suffering from hypothyroidism, levels of T3 and T4 thyroid hormones in his blood will be low. In many cases of feline hypothyroidism, your vet will be able to feel differences in the thyroid gland by palpitating your cat's throat.

Treating Feline Hypothyroidism

Hypothyroidism in cats is easily treatable with hormone replacement medication. These medications are prescribed according to your cat's weight, but your vet will monitor your cat's progress carefully during the initial stages of his treatment, to make sure his dosages are correct. Too few of the appropriate hormones won't alleviate your cat's hypothyroidism symptoms, while too many can cause feline hyperthyroidism. Your vet may need to adjust your cat's dosages several times; once your cat's medication is appropriately adjusted, he'll need followup treatment every six months to one year.

With treatment, most cats begin to improve rapidly. They become more active and show fewer behavioral problems within about a week. Hair will begin to regrow within the first week of treatment, though it may take some time to grow back completely. Most cats begin to lose excess weight within the first two weeks of treatment. Four weeks after your cat's final dosage adjustment, he should have largely recovered from the symptoms of feline hypothyroidism.

With proper treatment, your cat can live normally and enjoy a high quality of life with feline hypothyroidism. Treatment is as easy as administering daily oral medication, and the medications are generally inexpensive.