Graves' disease is a rare thyroid and autoimmune disease found in dogs with hyperthyroidism whereby the immune system produces excess antibodies in response to the increased production of thyroid hormones. Bacteria and viruses are believed to play a role in the development of graves disease, and a hereditary component is suspected, too.
Symptoms of Graves' disease vary but can include enlarged thyroid glands, increased blood pressure, irregular heartbeat, breathing difficulty, eye protrusion, weakness, hair thinning or loss, sinus infections, hypercalcemia, diarrhea, vomiting, hyperthermia, fever, increased thirst, increased urination, tremors and insomnia. Behavioral changes include hyperactivity and agitation. You may notice your dog is losing weight despite an increased appetite.
Treatment for Graves' disease focuses on immune system inhibition and reduction of thyroid hormones. Corticosteroids suppress the immune system but make your dog susceptible to other diseases or infections by reducing normal immune system responses. Medications, such as Tapazole, reduce thyroid hormone production. Radioiodine therapy and surgical removal of a lobe of the thyroid are other treatment options.