Thyroid Problems in Cats

Thyroid problems are caused by the malfunction of thyroid glands situated in the neck. The thyroid is an endocrine gland which produces thyroxin and other hormones. When the thyroid glands produce thyroxin in excess, the resulting condition is called hyperthyroidism; when the thyroxin is produced in smaller quantities, the cat has hypothyroidism.

In cats, hyperthyroidism is more common. Hypothyroidism usually appears as a consequence of hyperthyroidism treatment. While hyperthyroidism can be life threatening, hypothyroidism allows the cat to lead an almost normal life.

Symptoms of Thyroid Problems

Hyperthyroidism occurs when the excess thyroxin speeds up the metabolism. Hyperthyroidism is signaled by:

  • Increase in appetite, while the cat keeps loosing weight
  • Vomiting right after meals
  • Bald spots can appear in the cat's fur
  • Coarse fur
  • Oily skin and even acne, especially in the chin area
  • A foul-smelling liquid stool
  • The cat becomes very restless
  • Insomnia
  • Heart problems, due to the increased metabolism, which dictates a faster heart rate
  • Accumulation of fluid in the chest and respiratory symptoms
  • Kidney malfunction

Often, some symptoms of hyperthyroidism can be mistaken for those of old age, so tests are needed to establish the pet’s condition.

Hypothyroidism involves a slower metabolism and causes:

  • A decrease in appetite, while the cat is gaining weight
  • Constipation
  • Dry skin
  • The cat is sluggish,
  • The cat’s fur looses shine and becomes harsh just as in the case of hyperthyroidism.

Causes of Thyroid Problems in Cats

Hyperthyroidism is usually caused by the presence of a tumor on one or both thyroid glands. Tumors can be cancerous but only 2 to 3% of the cases are actually malignant.

Hypothyroidism typically appears after a hyperthyroidism treatment. The removal of thyroid glands as well as the radioactive iodine treatment for hyperthyroidism will cause symptoms of hypothyroidism.

Hypothyroidism can also be caused by deficiencies of iodine in the cat's diet.

Treatment of Thyroid Problems in Cats

As far as hyperthyroidism treatment goes, there are several options:

  • Anti-thyroid medication is the first and most common option due to the fact that this is less invasive and inexpensive. This type of treatment will not eliminate a tumor, but will keep the symptoms under control. Medication has to be given once or twice a day and the cat will be under constant monitoring for the rest of his life. There are side-effects such as vomiting and lethargy and more severe side-effects involving damage to the liver and the bone marrow.
  • Surgery is recommended when only one of the thyroid glands has to be removed. However, there is a risk that the other gland will become hyperactive or will develop a tumor in time. Surgery is also a very expensive solution and the cat has to be under anesthesia.
  • Radioactive iodine treatment can be the safest treatment as it only involves one injection, but it is an expensive treatment. After the treatment the cat has to stay in quarantine until the radiation levels are no longer dangerous.