Thyroid Testing in Dogs

The thyroid gland is an important endocrine gland in dogs. It helps regulate metabolism. Over or under active thyroid glands can cause health problems in the canine. Tests for thyroid function include blood draws and simulation tests followed by blood draws. These tests should be performed by a licensed veterinarian.

  1. Thyroid Gland

    • The thyroid gland produces hormones that help regulate the body's metabolism. It is located in the neck and has two lobes. The hormones produced by the thyroid gland are called T3 and T4. The amount of T3 and T4 produced by the thyroid gland is regulated by thyroid-stimulating hormones produced by the pituitary gland.

    Thyroid Disease

    • The most common types of thyroid disease are hypothyroidism and hyperthyroidism. Hypothyroidism is when the thyroid gland is under active and does not produce enough T3 and/or T4. Hyperthyroidism is the opposite; it occurs when the thyroid gland is over active and produces too much hormone.

    Blood Test

    • Aside from a physical examination of your dog, including feeling to see if the thyroid gland is enlarged, your veterinarian will take a blood sample from your dog and analyze it. The sample-taking process is relatively painless and will not cause your dog to suffer. Some vet clinics can analyze blood samples on site, while others may have to send the samples to an off-site lab to get the results.

    TSH Test

    • If your dog's blood sample results are abnormal, your vet may conduct a TSH test. For this test, the vet will inject some thyroid-stimulating hormone into your dog, wait several hours and then draw a blood sample. If the results indicate a more normal thyroid function, the vet may determine that it is not thyroid disease, but some other health condition, that is causing your dog's abnormal test results.

    Treatment

    • Treatment for hypothyroidism is generally a daily dose of synthetic thyroxine. It usually has to be taken for the duration of the dog's life. Hyperthyroidism treatment is similar, except the daily pill is a beta-blocker to inhibit TSH production.