Hypothyroidism in Dogs: Causes, Symptoms, and Treatment

How does hypothyroidism affect dogs?

Understanding hypothyroidism in dogs

The thyroid gland, located in your dog’s neck, is an important part of the endocrine system. It produces hormones that help regulate various bodily functions, such as metabolism, growth, and tissue maintenance. The two main hormones produced by the thyroid are thyroxine (T4) and triiodothyronine (T3), which play a vital role in maintaining your dog’s energy levels, weight, and even their coat condition. 

How does hypothyroidism impact dogs?

Hypothyroidism occurs when the thyroid gland is underactive, producing lower levels of T3 and T4 than required. This differs from hyperthyroidism, which involves an overproduction of thyroid hormones. Hypothyroidism can be congenital or acquired, with the most common cause being an autoimmune response where the dog's immune system attacks its thyroid gland.

Dogs with hypothyroidism often experience a slower metabolism, leading to lethargy, changes in their coat, and difficulty regulating their body temperature. It mainly affects middle-aged to older dogs and is more common in breeds such as Golden Retrievers, Cocker Spaniels, Dachshunds, and Poodles.

Is hypothyroidism dangerous for dogs?

While hypothyroidism can lead to more serious issues, such as nerve dysfunction, it is generally a manageable condition. If you notice signs of hypothyroidism in your dog, consulting your vet for a diagnosis and treatment plan can help manage the symptoms and allow your dog to return to normal activities. 

Symptoms of hypothyroidism in dogs

Often early warning signs of hypothyroidism in dogs will be indicators of the reduced metabolic rate - for example, your dog may start to gain weight, become lethargic, and seek out warm places in your home instead of their usual favourite spots.

Along with changes in behaviour like energy levels and seeking warm places, the most common symptoms of hypothyroidism in dogs include:

• A change in coat colour (dullness)

• Excessive hair shedding or thinning (unaccompanied by redness or rashes)

• General lethargy and disinterest in physical activity

• Weight gain (usually without an increase in appetite)

• Reduced ability to tolerate the cold (visible in shivering and seeking warmth)

• Increased susceptibility to skin and ear infections

Diagnosing and treating hypothyroidism

How to tell if your dog may be affected by hypothyroidism

Regular health check-ups with your vet can help detect hypothyroidism early. 

Because symptoms of hypothyroidism are broad and can be associated with numerous medical conditions, your veterinarian may follow up with lab tests to check your pet’s hormone levels (e.g. total T4 levels). Often a combination of baseline thyroid values (e.g. total T4 levels) and secondary thyroid tests are needed for a diagnosis of hypothyroidism - this is because a low total T4 in itself can be due to other illnesses/medications, so further testing is needed to confirm true hypothyroidism.

If results show that your pet may be affected, your veterinarian can then recommend any further diagnostic tests, and a treatment/management plan. 

How is hypothyroidism treated in dogs?

Hypothyroidism isn’t directly curable, but it is often easy to manage with the help of a prescribed management plan.

This plan commonly includes ongoing supplements of thyroid hormones, and periodically monitoring the thyroid hormone levels in the blood. With treatment, it is common that dogs will regain their energy, ability to regulate temperature, and their coat colour and thickness. 

Your treatment plan may vary, and as your pet ages and develops more of a tolerance to the thyroid replacement, the required dosage could change periodically too. Because of that, if your pet is taking hormone supplements, we recommend maintaining your regular check-ups every six months with your local vet. 

Continual communication with your veterinarian is the best way to help treat and manage your pet’s condition.

What to do if you think your pet may be affected by hypothyroidism

If you suspect your dog might be suffering from hypothyroidism, please don’t hesitate to contact us online or call our friendly reception team for a check-up.

Hypothyroidism is often easy to manage once diagnosed and it’s very common that pets can return to their day-to-day activities once on their recommended treatment plan.

Reedy Creek Veterinary Surgery offers a wide range of in-house pet services to pet owners including blood tests in both our hospital laboratory and external laboratories. We strive to deliver accurate results as quickly as we can to help pets return to their happy day-to-day lives. 

Our clinic is located on Scottsdale Drive in Varsity Lakes and is open Monday to Friday from 8 am to 5:30 pm and Saturdays from 8 am to 12 pm. Call our friendly team at (07) 5593 8395 within these hours to make an appointment for your pet, or book online now.