Hypothyroid Disease in Dogs

Just like their human owners, dogs can get hypothyroid disease as well. Is your dog overweight despite your attempts to drop those pounds? Does your dog lay around all day, seemingly lacking the energy you would expect him to have? Does he have ongoing problems with his fur or ears? If so, your dog may have hypothyroid disease. In the following article, I will discuss this condition in dogs, the diagnostic tests to identify this disorder, as well as the treatment options available.

With hypothyroid disease, it turns out that what you observe at home is as important as a diagnostic tool as what your veterinarian’s tests may suggest. A diagnosis of hypothyroid disease requires both an owner’s observation of clinical signs and confirmatory blood tests. Hypothyroid dogs are notoriously overweight and dull, lacking the energy to play with their toys or run around in the yard. They tend to be heat-seeking, preferring to lay in the sun, or by the heater vents of your home. They can have skin problems, and even Vomit more than usual.

In this author’s opinion, hypothyroid disease is both the most commonly overdiagnosed and underdiagnosed condition in veterinary medicine. This is because a single low thyroid hormone reading is not sufficient for a diagnosis. T4, the most commonly tested thyroid hormone, can be low for many reasons beyond that of hypothyroid disease. For this reason, a T4, Free T4 by equilibrium dialysis, and Thyroid Stimulating Hormone test along with clinical signs at home are required for a true diagnosis. But don’t let these technical terms scare you, they can all be acquired with a single simple blood draw. Lastly, elevated triglycerides (fats) and cholesterol are often noted on routine Bloodwork in hypothyroid dogs to help aid in diagnosis.

When these tests results are in congruence and with a history of behavior suggesting hypothyroid disease, a diagnosis can be made. Fortunately, it is a very manageable disorder. Levothyroxine is an oral medication used to control hypothyroid disease. After a few short weeks of starting this medication, your veterinarian will perform a follow-up blood test to confirm the optimal dosing for your dog. This simple blood test should be taken 4-6 hours after the administration of the medication. With treatment, the problems you’ve observed should noticeably improve. Your dog may have more energy, a healthier skin coat, and may even start losing weight! Those ongoing skin and ear problems may stop occurring and you may observe a happier, brighter dog at home.

Dogs with Hypothyroid Disease

If you suspect your dog has hypothyroid disease, I recommend making an appointment with your Veterinarian. Before this appointment, please note how much you are feeding your pet and what efforts you have made to reduce his weight. It is also important to note which other symptoms seem to make you think your dog may have hypothyroid disease, and if your dog has a history of ear or skin problems. During your appointment, your veterinarian will acquire a history from you and will likely suggest testing for the condition. Results should be available within a day or two, and your dog could be on his new medication shortly after. Hypothyroid disease is a manageable condition once diagnosed, and within no time your dog could be playing, running, and jumping like normal again.

Jeffrey Stupine, V.M.D
Medical Director
World of Animals Veterinary Hospital