Thyroid problems in dogs – types and treatments

Thyroid problems in dogs are fairly common and often treatable. Here are 2 types of thyroid disease in dogs, symptoms, and corresponding treatments.

What is the thyroid?

The thyroid gland is located in the dog’s neck and produces the hormone thyroxine (T4) along with other hormones. These play a major role in your dog’s metabolism and problems arise when they aren’t produced at normal levels. Thus, the thyroid is essentially the body’s thermostat.

Types of Thyroid Problems

fat bullodgHypothyroidism

Hypothyroidism occurs when your dog isn’t secreting enough thyroid hormones and this causes his metabolism to slow. This condition is more common in dogs than other animals.

In 95% of cases, it’s the destruction of the thyroid gland that causes hypothyroidism and is usually the result of either lymphocytic thyroiditis or idiopathic atrophy.

Other potential causes are medications such as corticosteroids, lack of exercise and exposure to toxins (including vaccinations).

Hypothyroidism shows these symptoms:

  • Mental dullness
  • Lethargy
  • Exercise intolerance
  • Cold intolerance
  • Weight gain without a change in appetite
  • Obesity
  • Changes in coat and skin such as hair thinning and shedding
  • Thickening of the skin
  • Reproductive disturbances

Some breeds appear to have a greater risk of this condition than others. Medium to large breeds are more susceptible whereas smaller breeds are less likely to develop problems.

Here are some of the breeds who are more genetically predisposed to the disease:

  • Cocker Spaniels
  • Airedale Terriers
  • Doberman Pinschers
  • Golden and Labrador Retrievers
  • Irish Setters
  • Greyhounds

Most dogs develop hypothyroidism between the ages of 4 and 10.

The Merck Veterinary Manual states that hypothyroidism is one of the most misdiagnosed diseases in dogs. This is because there are many diseases that mimic it. So,  your veterinarian can run a test for T3 levels which is generally included in a complete thyroid profile. She can also test for T4 concentration and this is a good initial screening for the disease. Another test is  the Free T4 and veterinarians consider it a more accurate evaluation of thyroid activity. Other tests may follow such as X-rays.

Treatment of Hypothyroidism

In most cases, your dog will need to take a synthetic thyroid pill for the rest of his life. However, if there is no autoimmune disorder, it’s possible to stimulate the remaining thyroid to begin working again through natural treatments.

Certified Veterinary Homeopath Dr. Jeff Feinman offers homeopathy which is a form of treatment based on the concept that “like cures like.” What this means is that a substance that normally causes an illness can cure that illness. The substance can come from a mineral, plant or animal and is usually highly diluted.

Hyperthyroidismcloseup of Greyhound

This is when the thyroid gland overproduces thyroxine. This condition is rarer in dogs than hypothyroidism and usually is caused by an aggressive tumor.

Raw food diets can also cause this condition. These include gullets, head meat and animal necks.

Here some of the symptoms of this disease:

  • Excessive weight loss
  • Increased appetite
  • Increased thirst
  • Frequent urination
  • Vomiting
  • Diarrhea
  • Weakness
  • Difficulty breathing
  • Irregular heartbeat
  • Excitability
  • Depression
  • Enlarged thyroid gland felt as a lump in the neck

Treatment of Hyperthyroidism

The treatment depends on the cause of the condition. Unfortunately, it’s more common for the disease to result from aggressive thyroid cancer. Treatment may include surgical removal of the tumor. Additionally, your veterinarian may administer chemotherapy and radiation. Benign tumors are easier to manage and may respond well to treatment. However, this is not so with malignant tumors as they can often spread. The earlier the treatment begins, the better the chance of recovery. In those cases where a dog recovers, dietary restrictions become part of the treatment and must be followed

Sometimes hyperthyroidism is caused by reaction to the medication for hypothyroidism. In this case, dosage can usually be adjusted until levels return to normal. If it’s caused by a diet that contains high levels of hormones, a dietary change is usually enough to reverse the condition.


Again, hypothyroidism is when your dog is not secreting enough hormone and hyperthyroidism occurs when he’s secreting too much hormone. So, if you get a diagnosis from you veterinarian, make sure you understand the difference. Also remember that hypothyroidism is much more common in dogs.

We love comments so be sure to leave yours below.


8 comments on “Thyroid problems in dogs – types and treatments

  1. Garen

    I know that the thyroid affects the metabolism of your dog.  Basically, how much energy your dog has.

    However, what about dogs and stress.  Meaning, I have a 3 year old laboratory retriever that gets really stressed out when I am not home for 1-3 hours.  He will frantically pace, rip up stuff, and wine constantly while we are not home.

    Does this have anything to do with the thyroid, though?

  2. Sondra Meyer

    Hi, I am so glad that I stumbled across your website.   I love it.    Recently, Francesco, my 6 year old toy poodle has started coughing a little bit when he gets excited.    Although I plan on getting him checked out at the vet, I felt compelled to do a little bit of internet research while I am waiting for the appointment.   

    Your article on thyroid problems in dogs is so well presented that I am confident that this is not his problem.   The lists of breeds predisposed to  hypothyroidism condition was helpful.   I also found the list of symptoms that you provided helpful.

    Although I feel bad that the extremely fat dog pictured is ill, it is kind of an amusing picture that is has got so fat…..   

    Well, keep up the great work on this website.   Thanks again.      

    1. Christopher Mitchell Post author

      Hi Sondra:

      Thank you for your kind words.

      That’s interesting you said that about the fat dog – I thought the same thing – I felt bad for him but at the same time the photo is amusing.

  3. Rob S.

    Let’s face it. People consider their dogs part of the family and why shouldn’t they?

    So you want your pet to be healthy and while you visit your doctor, you will be taking your dog to a vet to make sure that it is healthy as well.

    I’ve heard about hypothyroidism and hyperthyroidism in dogs because my sister has three dogs at any given time.She had this issue before. But she is always on top of things and takes her dogs to the vet regularly.

    But how often would you say your dog should visit the vet? Can they prevent his from happening?

    1. Christopher Mitchell Post author

      Hi Rob:

      Yes, dogs and any pet should be considered part of the family.

      Glad to hear your sister takes good care of her pooches!

      At least once a year for a checkup – twice a year ideally!


  4. Anusuya

    It is a great write-up about thyroid problem in dogs and it is great to know that there are well defined symptoms for diagnosis and treatment as well including homeopathy.

    I particularly like the T3 and T4 test for thyroid screening and profiling.

    I do not have a dog to offer my own experience. But my sister suffers from thyroid problem and on medication. Another relative has thyroid cancer and being treated. What I have gathered from different discussion forum is thyroid is a really sensitive organ and can be be impacted with fairly small changed in your environment, if you are stressed or scared for some reason. Thyroid keeps the body balance or equilibrium as per “Sadguru”. To have a healthy thyroid is related to living a mostly stress free life.

    Very helpful blog to help to know if your dog has thyroid problem and if the dog is suffering how to cure. 

    1. Christopher Mitchell Post author

      Hi Anusuya:

      Thank you for your comments.

      Sorry to hear about your relatives and their thyroid problems. Hope everything turns out well!


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