Hypothyroidism in Dogs
Veterinarian Reviewed on June 21, 2012 by Dr. Janice Huntingford
Hypothyroidism in dogs is a very common problem. Hypothyroidism occurs when the thyroid gland, a small gland in the neck adjacent to the windpipe, does not produce enough thyroid hormone. The thyroid gland is considered a master gland . It is responsible for producing thyroid hormones which have an effect on many parts of the body, including the skin and hair coat, metabolism, behaviour, attitude and even bone marrow function. In dogs, immune mediated disease and atrophy of the gland account for almost all cases.
Hypothyroidism generally develops in middle aged or elderly dogs and can occur in any breed although there are breeds that have a genetic tendency towards this problem. Breeds with definite predisposition to develop hypothyroidism include: the Doberman pinscher, the Golden retriever and Labrador Retriever, the Irish Setter, the Great Dane, the Dachshund, the Boxer, and the Beagle.
Clinical signs of Hypothyroidism are many and varied. Common signs include poor haircoat or loss of hair particularly along the sides,thickened skin, obesity, lethargy, anemia, a slow heart rate and elevated blood cholesterol. Neurological signs such as weakness, aggression and muscle atrophy can be seen but are not common. Megaesophagus ( an enlarged esophagus) and laryngeal paralysis ( a cause of roaring in dogs) as well as infertility have also been linked with hypothyroidism.
Hypothyroidism is diagnosed with a blood test or a series of blood tests that measure T4, T3, TSH or autoantibodies. The conventional treatment of this condition is replacement of the hormone with a synthetic hormone and this treatment usually works quite well. There is a natural canine thyroid glandular from Standard Process which may or may not be effective. There is also a natural thyroid supplement that is used for humans but it is considerably more expensive than the synthetic hormone. Chinese herbs and homeopathy can also help. Most of the thyroid supplements should have Kelp in some form, Astragalus and Eleutherococus Senticosus. These are contained in the herbal supplement Thyro-Up and it can help if the thyroid has not been totally destroyed. However if the thyroid has been totally destroyed, supplement with the hormone L-thyroxine has proved to be the most effective treatment. I always like to supplement these dogs’ diets with Seaweed as this is helpful.
Our Expert

Janice Huntingford, DVM, has been in veterinary practice for over 30 years and has founded two veterinary clinics since receiving her Doctor of Veterinary Medicine at the Ontario Veterinary College, University of Guelph. She has studied extensively in both conventional and holistic modalities. Ask Dr. Jan