Feline Hyperthyroidism

Feline Hyperthyroidism is a disease that commonly occurs in middle aged and geriatric cats. Hyperthyroidism is a result of the thyroid gland over producing the hormone T4. The excessive T4 causes the metabolic rate to increase and the thyroid gland to become enlarged. Cats that have hyperthyroidism typically show symptoms of increased appetite while losing weight, excessive thirst and urination, and sometimes hair loss.

Feline Hyperthyroidism is diagnosed by checking the levels of T4 and T3 from a blood sample. Cats with hyperthyroidism frequently experience a reduced quality of life due to weight loss, muscle deterioration, chronic vomiting or diarrhea. In addition, some hyperthyroid cats present less visible signs of the disease such as heart disease and high blood pressure. Left untreated, these problems can result in heart failure, sudden blindness, or sudden death. However, these conditions can be prevented with timely treatment for thyroid disease.

About The Thyroid Gland

The thyroid gland is composed of two lobes located on each side of the wind pipe. This gland produces the hormones T3 (Triiodothyronine) and T4 (Thyroxine) which are responsible for maintaining the body’s normal metabolic rate. Once T4 is released from the gland, it is absorbed by the body’s tissues and then converted into T3. T3 effects every cell of the body because it affects how hard and fast those cells work.

Radiotherapy for Feline Hyperthyroidism

Radiotherapy is the safest and most effective method of treatment for feline hyperthyroidism. In this non-invasive treatment, the hyperthyroid cat is given an oral dose of radioactive iodine (Radio-iodine or I131). The radio-iodine then seeks and destroys the abnormal thyroid tissue without endangering other organs. The radio-iodine may even allow the thyroid gland to return to normal function. While most cats regulate their thyroid levels within one month, a small number can take up to three months. By law, the treated cat must stay hospitalized for at least 3 days post treatment. This ensures radiation levels are sufficiently safe for the cat to be with their owners.