Hypothyroidism in Dogs

posted: by: Rachel, LVT Tags: "Clinic Specials" "News" 

Hypothyroidism in Dogs


What is Hypothyroidism?

            Hypothyroidism results from a lack of thyroid hormone production by the thyroid glands, which are located in the neck near the voice box. Middle-aged and older dogs are more commonly diagnosed with this disease.

 Symptoms can include:

·         lethargy/fatigue

·         sleeping for longer periods of time

·         dull attitude

·         weight gain

·         thickened skin

·         dry, loose hair coat

·         hair loss, lack of regrowth after shaving.

·         poor wound healing

·         heat seeking behavior due to feeling cold



How do you diagnose Hypothyroidism?

            A thyroid level blood test allows a veterinarian to evaluate the function of the thyroid gland. This test measures the amount of thyroid hormones in the blood. Thyroid hormones are responsible for the regulation of cell metabolism in the body and will slow down when thyroid hormones are low or speed up when they are too high.

            When there is not enough thyroid hormone circulating in the body, several body systems will be affected and result in one or many of the symptoms above.

            Thyroid testing is performed when a veterinarian suspects that your dog may have a hormone imbalance by a routine blood test. There are a few different types of tests than can be run depending on what the veterinarian is looking for.


Types of tests for Hypothyroidism

            The total T4 (TT4) is normally used as a screening test for initial diagnoses. This test measures the amount of thyroid hormone that the thyroid gland is producing. When a TT4 falls below the reference range, veterinarians will recommend either a Free T4 or a Full Thyroid Panel to confirm hypothyroidism and help determine the cause. These tests can also be used if the initial TT4 is normal but the veterinarian still suspects hypothyroidism.

            Once hypothyroidism is confirmed and daily treatment is started, another TT4 will be used to determine if the dose of medication provides enough hormones for your dog’s cells to function normally or if it needs to be adjusted.


Treatment of Hypothyroidism

            Treatment is administered by an oral thyroid hormone supplementation. There is usually a rapid improvement in your pet’s activity once treatment has started. However, regrowth of the hair and improvement of skin may take several months. Occasionally a pet may experience sensitivity to the amount of thyroid supplementation given. Signs may include: rapid heart rate, increased water intake/urination, change in temperament, or weight loss. Please contact your veterinarian if any of these signs occur.

            Routine blood tests should be done every 6 months to ensure adequate supplementation. Treatment for hypothyroidism is life-long because there is no cure.



If you think your dog is experiencing one or any of these symptoms please call Herkimer Veterinary Associates.