Hypothyroidism in Dogs: Symptoms and Treatment

If your dog is suffering from weight gain, hair loss, and skin issues, hypothyroidism could be the underlying cause. Fortunately, this condition is not life threatening for your dog and can often be managed with medication once it is diagnosed.

What is Hypothyroidism?

Hypothyroidism is an endocrine (hormone) disorder related to the thyroid glands, which are small glands in your dog’s throat near the larynx or voice box. They have a number of important functions in the body including producing hormones that help regulate metabolism. Hypothyroidism occurs when these glands do not produce enough thyroid hormone and cause your dog’s metabolism to slow down.

There is another kind of thyroid disease that is rarely seen in dogs, but it is common in cats. This is hyperthyroidism, which happens when the glands produce too much thyroid hormone. It has the opposite effect of speeding up your dog’s metabolism and can cause symptoms such as hyperactivity, restlessness, a rapid heart rate, panting and eventually weight loss in spite of an increase in appetite.

Have a cat at home? Learn about hyperthyroidism and how it can affect your feline friend.

Dogs at Risk

Dogs of any age or breed can suffer from hypothyroidism, but it is more prevalent in medium to large-sized dogs, such as Doberman Pinschers, Golden Retrievers, and Irish Setters. It has not been reported as frequently in German Shepherds and mixed breeds. Hypothyroidism is typically diagnosed in middle-aged dogs from around 4 to 10-years-old.

symptoms of hypothyroidism in dogs _ Irish setter with wet ears and a green collar

Signs of Hypothyroidism

The signs of hypothyroidism can be subtle and hard to detect especially in the early stages. They can include:

A low thyroid hormone level can also affect mental sharpness. It can make a normally alert and curious dog seem distracted or slow to respond to commands.


Hypothyroidism can be due to a disease called autoimmune thyroiditis that causes the body’s immune system to attack the tissues of the thyroid gland. This underlying disorder harms the gland making it unable to produce enough thyroid hormone to support normal function. Occasionally, certain medications such as steroids can also impact the production of thyroid hormones and lead to hypothyroidism. In addition, this condition can be caused by a neck injury that damages the thyroid.

causes and diagnosis of hypothyroidism in dogs _ smiling Golden Retriever with brown collar

Diagnosis and Treatment

While hypothyroidism is not usually a life-threatening disorder, it can negatively impact your dog’s quality of life, so it is important to visit your veterinarian for proper diagnosis and treatment.

During the visit, your veterinarian will ask about your dog’s symptoms and conduct a full physical exam. A blood test can also be done to check the level of thyroid hormones called thyroxine (T4) and triiodothyronine (T3). Additional diagnostic tests may also be needed to rule out other illnesses and evaluate the overall health of your dog.

An ASPCA Pet Health Insurance plan can help you manage the costs of diagnosing common ailments like hypothyroidism. Get a quote for your dog now.

Treating Hypothyroidism

Hypothyroidism cannot be cured, but it can be managed through medication. Dogs with this disorder are prescribed a synthetic thyroid hormone called thyroxine that will need to be given for the rest of the dog’s life. Follow-up blood tests can help ensure the dog is receiving the right dosage of the medication to properly regulate thyroid hormone levels. If you inadvertently give too much thyroxine, you can cause hyperthyroidism.

Tips to Give Your Dog a Pill

If your dog needs to take thyroxine or any other kind of medication in tablet form, it can be tough to get them to swallow it down. Here are a few ways to help your dog take a pill:

  1. Wrap it up – You can wrap the pill up in a bit of cheese or a piece of sliced turkey. Just make sure your dog doesn’t eat the tasty “wrapper” and spit the pill out on the floor.
  2. Hide it in a meal – You can try hiding the tablet in a bowl of wet dog food. This technique works better for dogs who gobble up their food quickly. Slower or more discerning eaters might pick around the pill, which is why you should always watch to make sure the pill is eaten up.
  3. Coax it in– Have your dog sit in front of you and gently open their mouth. Carefully place the pill near the back of the throat and close the mouth. Lightly hold your dog’s jaw shut until they swallow it down. Be sure to offer lots of praise for a job well done.

Get more tips on giving your dog or cat a pill.

preventing hypothyroidism in dogs _ elderly Boxer dog


There is no way to prevent hypothyroidism, but regular veterinary visits can help your dog’s doctor diagnose conditions like this sooner rather than later. You can get reimbursed for an annual exam and other routine wellness services if you have an ASPCA Pet Health Insurance plan with preventive coverage.

It also helps to do everything you can to support your dog’s well being. For instance, brush their teeth regularly, make sure they get a good dose of daily exercise, and feed them a nutritious diet of high-quality dog food. You can supplement their diet with a variety of safe people foods, such as bits of skinless cooked chicken, boiled sweet potato, and apple slices.* And of course, shower your four-legged friend with all of the love and attention they deserve!

Are you financially prepared to care for your dog in case of an illness like hypothyroidism? Learn more about coverage options for your dog.

Reminder: Treats such as these should not make up more than 10% of a pet’s caloric intake. Also, stomach upset may occur in pets who do not tolerate dietary changes well.


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