Thyroid Gland in Cats

The feline endocrine system is responsible for producing hormones that are needed for the body to properly function. There are many different organs that are involved in this process, including the pituitary gland, the adrenal gland and the thyroid gland. As a part of the endocrine system―also known as the hormone system―the thyroid gland is important for many feline body functions.

  1. Identification

    • The feline thyroid gland is a dark red color. It's exact size can vary based on the breed of the cat as well as the cat's individual body characteristics. It is elongated in shape, described as similar in appearance to a bow tie or a butterfly; mostly because it features two lobes. In a healthy cat, the thyroid gland is not palpable beneath the skin.

    Location

    • Located in the frontal area of the neck, the thyroid gland sits beneath the voice box, or larynx. The two lobes of the thyroid gland are situated on either side of the cat's windpipe. Dr. Bari Spielman of PetPlace.com adds that each side of the gland is deeply embedded into the neck tissues that surround the larynx.

    Functions

    • The thyroid gland produces several different hormones, and it is controlled by the pituitary gland in the brain. Hormones produced by the thyroid gland are important for regulating metabolism and producing proteins. The thyroid gland also works together with the hormones produced by the parathyroid to control and maintain the calcium balance within the cat's body.

    Diagnostic Tools for Thyroid Evaluation

    • When diseases occur, the veterinarian may need to evaluate the function of the thyroid gland. Most diagnostic tools work by measuring the levels of the T3 or T4 hormones. For example, cats who are suffering from hyperthyroidism will have elevated levels of the T4 hormone, whereas cats with hypothyroidism will have lowered levels of both the T3 and T4 hormones. These numbers are not always accurate and additional tests such as T3 suppression tests, radioactive iodine scans, fine needle aspiration, CT scans or a cytology will need to be performed.

    Thyroid Gland Diseases

    • Hypothyroidism, while common in dogs, is relatively rare in cats. Hypothyroidism occurs when the thyroid gland is no longer producing adequate levels of hormones, resulting in lethargy, weight gain and changes in the cat's fur quality. However, thyroid gland diseases such as hyperthyroidism are common in older and middle-aged cats. In hyperthyroidism, the thyroid gland produces excessive levels of hormones, which leads to an increase in appetite, weight loss, vomiting, diarrhea and excessive activity.

      Unfortunately, as with any other part of the body, the thyroid gland may also develop tumors. While the majority of these tumors are benign, they can result in hormonal imbalances.