Did you know that hypothyroidism is the most common hormone imbalance in dogs? Similar to humans, we know that iodine deficiency leads to the thyroid gland (located near the dog’s throat). However, dogs do not show that classic goiter that is often seen in humans with hypothyroidism. Instead, common histories include dogs that are slowing down, gaining unexpected weight, unresolving skin infections, hair loss, brittle or dry coats, changes in their facial appearance and lethargy. Some dogs in fact may show no true clinical signs of hypothyroidism unless it is detected on a blood test.

At least treatment of hypothyroidism is relatively straightforward and fortunately affordable. Hypothyroidism is treated with oral administration of thyroid hormone (T4). Pills are given usually twice daily to start but may be dropped to once a day after good thyroid control has been achieved, pending veterinary instructions. It is paramount that a pet parent does not change the dosage and frequency without consulting with their veterinarian first. Treatment is given for the rest of the dog’s life.

Similar to any long term medication for pets (seizure medications, arthritis medications, etc.) periodic blood testing is important to understand regulation. In the case of hypothyroidism treatment, it is important to know if the medication dose is too low or too high. Thyroxine (T4) is a safe medication but if it is not given in adequate doses per recommendations, the dog will not be adequately regulated. If the dose is too high and given for too long a time, excessive water consumption, weight loss, and irritability can result. Always consult with your veterinarian should you have any additional questions or concerns regarding your dog’s hypothyroidism.

Adam Christman, DVM, MBA

Chief Veterinary Officer
MJH Life Sciences