Canine hypothyroidism, also known as hypothyroid disease, is a common hormonal disorder in dogs. It is most commonly caused by non-cancerous changes to the thyroid gland resulting in decreased thyroid hormone levels in the blood. The thyroid gland secretes thyroid hormone which affects the metabolic function of almost all organ systems, including heart, respiratory, nervous and musculoskeletal systems. Canine hypothyroidism is typically found in dogs that are middle-aged and older. Although many breeds can be affected, Doberman Pinschers and Golden Retrievers are the most commonly reported breeds at risk.
Clinical signs or changes you can see in your pet result from a decreased metabolic rate and can include:
It’s important to pay close attention to your dog’s physical and behavioral changes as they age. Remember to bring any noticeable changes to your veterinarian’s attention, so they can perform the proper tests for diagnosis.
If your dog has clinical signs that may be consistent with hypothyroidism, your veterinarian may recommend the following testing:
If hypothyroidism is confirmed in your dog, a daily thyroid hormone medication will be prescribed for the duration of your dog’s life. This medication should return your dog’s T4 levels to normal and symptoms will resolve. It is important to continue this medication indefinitely or signs could return.
Routine monitoring of thyroid level is needed to adjust medication doses, especially during the initial phases of treatment. Your veterinarian will recommend that your dog return for exams and routine T4 testing until the proper dose of medication is determined.
Once the proper dose is determined, your dog will continue to be monitored on a regular basis to ensure the thyroid does not become overactive. Your veterinarian may need to make further adjustments to the dose of medication for your dog.
With proper medication and monitoring, your dog’s clinical signs will improve, and they can enjoy a normal life.