Hypothyroidism In Dogs: Symptoms, Causes & Treatment

Pet parents should always be aware of common ailments that may affect their dog's quality of life. One common dog illness is hypothyroidism, an endocrine disease. Hypothyroidism is non-life-threatening when treated correctly, although it is not curable. It occurs when a dog's thyroid gland doesn't produce enough of a certain hormone called thyroxine (T4), which regulates the metabolism.¹

Hypothyroidism in dogs is manageable, and many dogs can live long and healthy lives after diagnosis. Keep reading to learn more about hypothyroidism in dogs, including symptoms, causes, and treatment.

• What Is Hypothyroidism?
• Symptoms Of Hypothyroidism In Dogs
• Causes Of Hypothyroidism In Dogs
• Hypothyroidism In Dogs Treatment
• Hypothyroidism In Dogs: FAQs
• Final Notes

What Is Hypothyroidism?

Hypothyroidism in dogs is a condition of the thyroid in which it is not producing enough hormones. Ultimately, it means your dog isn't getting enough hormones that regulate their metabolism because their thyroid gland isn't working properly, which can result in symptoms including weight gain, lethargy, hair loss, and more.²

Breeds Predisposed To Hypothyroidism

Hypothyroidism occurs when the thyroid gland is either inflamed or shrinks and is most common in medium to large breeds.³

Some breeds predisposed to hypothyroidism include:

• Golden Retriever
• Doberman Pinscher
• Irish Setter
• Miniature Schnauzer
• Dachshund
• Cocker Spaniel
• Airedale Terrier

Hypothyroidism is common in both males and females. However, research suggests that spayed females may be at an increased risk of developing hypothyroidism.²

Symptoms Of Hypothyroidism In Dogs

Common signs of hypothyroidism in dogs are related to the slowing of metabolism due to the inability of the thyroid gland to produce enough hormones.²

Symptoms include:

• Lethargy: If your dog is lethargic, they may sleep more or stop engaging in playful activity. Instead, they may lie around the house and would rather nap than go for walks.
• Weight gain: Weight gain can occur with or without an increase in appetite. If your dog isn't eating any more than usual and still gaining weight, it could indicate a thyroid problem. Knowing how much your dog weighs and should weigh is an important part of being a pet parent, so it's always best to weigh your dog regularly and pay attention to their weight at the vet, which may be more accurate than using a scale at home.
• Obesity: Weight gain can lead to obesity in pets that can cause other health problems, so if your pet is gaining weight rapidly with no changes in their diet, it's best to take them to the vet for a checkup to help prevent obesity and diabetes.
• Haircoat changes: Dogs with hypothyroidism may have a thinning coat on their back or sides, but they can lose hair anywhere.¹
• Heat-seeking: Dogs with hypothyroidism may feel cold and seek out warmer areas, such as laying in the sun or going outside more often on warm days.²

Dogs with hypothyroidism can suffer from one or more of these symptoms. They may feel lethargic because their metabolism has slowed, affecting their ability to produce energy. Additionally, many dogs gain weight from hypothyroidism because the body isn't properly metabolizing food, so it's unable to use all of their nutrients for energy. Hypothyroidism can cause weight gain without changing their food, eating habits, or activity levels. However, some dogs might have an increased appetite as their body's way of trying to produce more energy, which can lead to obesity.

Your dog's coat can also be affected by hypothyroidism. Dogs with this disease often face excessive shedding and stunted hair growth. However, you may also notice thinning fur or alopecia.²

Additionally, dogs with hypothyroidism may feel colder because of their slower metabolism, which may lead to a lower core temperature.¹

Causes Of Hypothyroidism In Dogs

There are two common causes of hypothyroidism in adult dogs, including lymphocytic thyroiditis and thyroid gland idiopathic atrophy. Secondary hypothyroidism in dogs is due to the growth of a fatty tumor that can cause atrophy of the gland and surrounding pituitary tissues.² However, lymphocytic thyroiditis is an immune disease that occurs when the immune system attacks the thyroid, although the reasons for this are unclear. A rare cause of hypothyroidism in dogs is cancer.

Dogs are rarely born with thyroid issues. However, puppies can be born with pituitary disorders, such as dwarfism, and hypothyroidism.⁴

Hypothyroidism In Dogs Treatment

Treatment in dogs with hypothyroidism first requires diagnosis to help your vet understand what might be causing your dog's symptoms. The easiest way for a vet to diagnose a dog with hypothyroidism is with blood testing, which consists of multiple tests to determine the presence of any other diseases and rule them out.³

The standard treatment for hypothyroidism in dogs includes a synthetic hormone called levothyroxine or L-T4, which can restore the thyroid hormones and reverse the signs of the disease.² This medication is given twice daily by mouth, and eventually, some dogs may only need it once a day.³ However, all dogs will need to remain on medication for the rest of their lives.

Most pet parents and vets will recognize that hormone replacement therapy is working by monitoring the dog's symptoms. The first signs the treatment is effective are positive changes in the dog's coat and weight after the first few months.² If treatment is not working, a vet may adjust the dosage or help the pet parent understand the importance of giving their dog their medication correctly. However, it's also possible a vet's diagnosis is incorrect, and they're treating your dog for hypothyroidism when your dog is actually suffering from another illness.

Hypothyroidism in dogs is non-life-threatening, but managing the illness can drastically improve your dog's quality of life.¹ Additionally, treatment is important because it can prevent weight gain that leads to diabetes, which can be life-threatening. Once your dog is diagnosed with hypothyroidism, they'll have to take their oral medications daily to ensure optimum health and wellness.

Even though the management of hypothyroidism in dogs requires lifelong therapy, it's a fairly easy process for pets and their pet parents. Your dog's treatment may change from time to time due to medication tolerance, so your dog's thyroid levels should be checked at least once to twice per year. Luckily, you should already be visiting your vet at least once a year for your dog's annual wellness visit, so you can get two vet appointments in one by having them check your dog's thyroid levels along with their general health condition.

Unfortunately, there is no guaranteed way to prevent hypothyroidism in dogs. Visiting your vet annually can help them catch potentially dangerous illnesses and begin treatment earlier, improving your dog's quality of life as soon as possible. Additionally, even though you can't prevent hypothyroidism, you can prevent other types of illnesses that can be life-threatening to dogs.

Taking care of your pet's general wellness can improve their quality of life and help them live longer, healthier, happier lives. Some things you can do at home to support your dog's health include brushing their teeth regularly, monitoring their weight, and ensuring they get enough exercise and mental stimulation. You can also improve their health through their diet by teaming up with your vet to find a balanced diet ideal for your pet based on their life stage, activity levels, and any existing medical illnesses.

Hypothyroidism In Dogs: FAQs

What is a common sign of hypothyroidism in dogs?

Common signs of hypothyroidism in dogs include weight gain, lethargy, and heat-seeking. If your dog seems more tired than usual and they've been gaining weight without a change in their eating habits or diet, it could indicate hypothyroidism. However, you won't know until you visit the vet. Your vet is the only person who can diagnose hypothyroidism in dogs and treat your dog to help you manage their illness and improve their quality of life.

How long do dogs with hypothyroidism live?

Dogs diagnosed with hypothyroidism will get treatment for their disease for the rest of their life. However, the life expectancy for dogs with hypothyroidism is normal. Most dogs go on to live full lives as long as they receive their treatment. While hypothyroidism isn't curable, it is easily manageable. Dogs that are treated for hypothyroidism may see improvements in their symptoms within just a few months.

Of course, the earlier you can have your dog diagnosed with hypothyroidism, the better their outcome will be. As soon as you notice any of the symptoms of hypothyroidism in dogs, it's best to consult your vet to help determine whether your dog has hypothyroidism or another medical concern..

What happens if canine hypothyroidism goes untreated?

If hypothyroidism goes untreated, it can shorten a dog's lifespan because the thyroid gland affects the dog's ability to metabolize food into energy. In addition, dogs with untreated hypothyroidism can develop fatal illnesses, such as obesity and diabetes, high cholesterol, and decreased immune function. Once your dog is diagnosed, treatment requires daily oral medication and vet visits to monitor their hormone levels at least once or twice a year. Ultimately, treatment is easy, and it can dramatically improve your dog’s quality of life while preventing life-threatening complications.

Final Notes

Hypothyroidism in dogs isn't preventable, and some breeds are predisposed to this illness. Luckily, hypothyroidism is manageable in dogs with the help of your vet. However, common signs of hypothyroidism in dogs can look similar to other illnesses, so it's important to get your dog diagnosed by a vet to rule out any other conditions. In addition, because hypothyroidism can lead to severe health complications, starting treatment as soon as possible is best.

It's always best to have a vet you trust regarding your pet's health. That's why we're here. Dutch's telemedicine for pets can help you treat various health conditions in dogs. We work with pharmacies to help you buy medication for pets online from the comfort of your home while providing professional advice from licensed vets to help you better care for your dog's health. So whether you need advice on how to care for your dog with hypothyroidism or you're worried about their diet and nutrition, Dutch is here to help. Join us today to schedule your dog's first telemedicine appointment.