Hypothyroidism in dogs

Hypothyroidism often develops gradually. You might first notice that your dog seems less keen on walks, gains weight or starts losing fur.

The good news is that most dogs do well with treatment. They usually need medication for life, along with regular blood tests. Lifetime dog insurance may help towards eligible treatment costs.

What is hypothyroidism in dogs?

Hypothyroidism develops when the thyroid gland (located in your dog’s neck) doesn’t make enough of certain hormones. These hormones help control your dog’s metabolism and how their body uses energy.

This can affect your dog’s energy levels, weight, skin, coat and other parts of their health.

Causes of hypothyroidism in dogs

In most cases, hypothyroidism develops because the thyroid gland becomes damaged over time. This may happen when the immune system attacks the gland. Sometimes the gland shrinks for reasons that aren’t clear.

Less commonly, hypothyroidism can be linked to another problem affecting the thyroid gland or the part of the brain that controls it. There’s usually nothing an owner could’ve done to prevent the condition.

Commonly affected breeds

Any dog can develop hypothyroidism. However, research by the Royal Veterinary College found that some breeds have a higher risk, including:

• Dobermanns

• Tibetan Terriers

• Boxers

• Alaskan Malamutes

Being a higher-risk breed doesn’t mean your dog will develop hypothyroidism. Crossbreeds can be affected too.

Types of hypothyroidism in dogs

Vets may describe hypothyroidism according to where the problem starts.

• Primary hypothyroidism starts in the thyroid gland itself. This is the usual type in dogs.

• Secondary hypothyroidism starts when the part of the brain that tells the thyroid gland to work doesn’t send enough signals. This is rarer.

A dog can also have a low thyroid hormone result without having hypothyroidism. Other illnesses and some medicines can affect the test result. Your vet will consider your dog’s symptoms and may recommend further tests before making a diagnosis.

Symptoms of hypothyroidism in dogs

The signs of hypothyroidism in dogs often appear slowly and can be easy to miss at first. They may include things like:

• Weight gain without an obvious increase in food

• Tiredness or less interest in exercise

• Feeling the cold more than usual

• Hair loss or a thinning coat

• Dry, dull or flaky skin

• Repeated skin or ear problems

These signs can have several causes. Weight gain or hair loss alone doesn’t mean your dog has hypothyroidism.

What to do if your dog shows signs of hypothyroidism

Book an appointment with your vet if your dog is gaining weight, seems unusually tired or develops changes to their skin or coat. Your vet will ask about the changes you’ve noticed and examine your dog. They may recommend blood tests to check thyroid hormone levels and look for other causes.

A single low thyroid hormone result may not confirm hypothyroidism. Your vet might need additional tests or to repeat a test before recommending treatment. Tell them about any medicines your dog takes, as these can affect the results.

What age could you expect hypothyroidism in your dog?

Hypothyroidism is more likely to be diagnosed as dogs get older, although younger dogs can develop it too.

Because the changes often happen slowly, they may look like ordinary signs of ageing. If your dog seems less active or their coat changes, it’s worth speaking to your vet.

How to manage hypothyroidism in dogs

Most dogs with hypothyroidism need thyroid hormone replacement medication for life. Give it as your vet directs.

Your vet will arrange follow-up appointments and blood tests to check how well the treatment is working. They may adjust the dose as your dog’s needs change.

At home, keep track of your dog’s energy, weight and skin or coat changes. If symptoms return, speak to your vet before changing the dose yourself.

Does pet insurance cover hypothyroidism in dogs?

Pet insurance may help towards the cost of diagnosing and treating hypothyroidism. This depends on your policy and whether the condition is eligible for cover.

Eligible costs might include vet appointments, blood tests and prescribed medication. Because treatment is usually lifelong, it’s worth checking how your policy covers ongoing conditions.

As with most pet insurance, pre-existing conditions aren’t usually covered. Check your policy documents to see what’s included and what limits apply.

Hypothyroidism treatment options

The usual treatment is a thyroid hormone replacement medicine called levothyroxine. Your vet will prescribe a dose for your dog and check their response with blood tests.

Many dogs begin to seem more energetic after starting treatment. Changes to the skin and coat can take longer to improve.

Hypothyroidism usually needs treatment for life, but dogs can often enjoy a good quality of life with the right dose and regular checks. Your vet can also treat any related skin or ear problems.

When to speak to a vet

Contact your vet if your dog gains weight without an obvious reason, becomes unusually tired or develops hair loss or recurring skin problems.

If your dog already has a diagnosis, speak to your vet if their symptoms return or they seem unwell after starting medication. Their dose may need reviewing, or something else may be affecting their health.

With treatment and regular monitoring, most dogs with hypothyroidism can get back to enjoying their usual routines.