Adopting a Dog with Hyperthyroidism: What You Need to Know

You visited a shelter and instantly fell in love with a dog, but the staff informs you the dog has hyperthyroidism. Naturally, you wonder what adopting a dog with hyperthyroidism entails. How much extra care do they need? What does treatment look like? And is this condition manageable for the average pet parent?

Adopting a dog with hyperthyroidism will require extra care, but it can be a worthwhile choice for those prepared to meet their needs. Here’s a guide to everything you need to know about caring for a dog with hyperthyroidism, from treatment options to daily care.

What causes hyperthyroidism in dogs? 

Hyperthyroidism is a condition that occurs when the thyroid gland in the neck produces an excess of hormones. 

“Hyperthyroidism in dogs is rare and most commonly caused by a tumor of the thyroid gland,” says Dr. Carol Osborne, author and integrative veterinarian at Chagrin Falls Pet Clinic. She adds that elderly canines, especially Golden Retrievers, Huskies, and Boxers, are most prone to hyperthyroidism.

In some cases, giving a dog with hypothyroidism (a sluggish thyroid) too much oral thyroid hormone can lead to hyperthyroidism. In these instances, Dr. Osborne explains, blood tests are used to confirm the issue, and treatment with methimazole, an oral medication, may be prescribed to reduce hormone levels.  

Some research also suggests that raw meat diets, particularly those containing thyroid tissue from other animals, may contribute to elevated thyroid levels. Additionally, consuming foods or supplements that contain kelp or seaweed, which are high in iodine, can increase the risk of hyperthyroidism in dogs.

Signs of hyperthyroidism in dogs

Hyperthyroidism in dogs can create a variety of symptoms, many of which may mimic other health issues. This makes it important for pet parents to bring their dogs to the vet for a thorough evaluation.

Symptoms of hyperthyroidism in dogs may include the following.

• Weight loss: One of the hallmark signs of hyperthyroidism is unexplained weight loss, even when your dog is eating as much or more than usual.

• Increased thirst and frequent urination: Dogs with hyperthyroidism often drink more water than normal, which can lead to more frequent urination.

• Hyperactivity or restlessness: Excess thyroid hormones can make your dog more energetic than usual, leading to restlessness, pacing, or difficulty settling down.

• Rapid heart rate or irregular heartbeat: Hyperthyroidism can cause the heart to beat faster or develop an abnormal rhythm, which your vet can detect during a routine exam.

• Enlarged thyroid gland: In some cases, the thyroid gland may become enlarged and form a lump in the neck area, which might be visible or palpable.

• Vomiting or diarrhea: An upset digestive system, including vomiting and diarrhea, can occur in dogs with hyperthyroidism, often due to the increased metabolic rate.

• Changes in coat quality or excessive shedding: You may notice changes in your dog’s coat, such as thinning fur, a dry texture, or excessive shedding, which can be another sign of an overactive thyroid.

How do you treat hyperthyroidism in dogs? 

Treatment for hyperthyroidism in dogs depends on the cause of the disease. Dr. Osborne notes that while the condition can generally be treated, it often can’t be cured. Your veterinarian will design a treatment plan based on the underlying issue and your dog’s specific condition. The following are common treatment options.

Surgery 

“The treatment for hyperthyroidism in dogs caused by thyroid cancer involves surgical removal of one or both cancerous thyroid glands,” Dr. Osborne says. On average, after the surgical removal of the cancerous thyroid, the dog’s lifespan can be extended by one to three high-quality years, assuming the mass is small, not attached to surrounding tissue, and hasn’t spread to the lymph nodes or blood, she explains. 

If a thyroid tumor is attached to surrounding tissue, complete surgical removal may not be possible. In such cases, a surgeon can often remove a significant portion of the tumor and follow up with chemotherapy and/or radiation therapy to target any remaining tumor cells. In these cases, survival is usually under a year. 

After surgery, the dog will need to take Synthroid, an oral synthetic thyroid hormone, since they will no longer be able to produce thyroid hormones naturally, Dr. Osborne adds. 

Change in diet

If hyperthyroidism is linked to dietary factors, such as feeding a raw meat diet, switching to a different food plan may resolve the condition. Additionally, Dr. Osborne says a low-carb diet may be recommended, as it can help manage thyroid hormone levels by reducing the intake of foods that may exacerbate the condition. 

Adjustment of medication

If hyperthyroidism is caused by overuse of the hormone medication treating hypothyroidism, a veterinarian may adjust the dog’s medication to balance thyroid hormone levels. Regular blood work is essential to ensure hormone levels stay within a healthy range.

Tips for living with a hyperthyroid dog

The time you have with your newly adopted dog will depend on the cause of their hyperthyroidism. In cases where the condition limits their lifespan to just a year or two, providing a loving home is a deeply compassionate, rewarding choice. Giving dogs comfort and care during their remaining years will make a meaningful impact. 

If the hyperthyroidism is due to overmedication or diet, proper treatment can allow your dog to live a normal, full life. 

Regardless of the cause, both situations require commitment and ongoing care. Here are a few tips to help you navigate life for a dog with hyperthyroidism.

Stick to a medication and diet routine

If your dog is prescribed medication, like methimazole or Synthroid, it’s crucial to follow the dosing schedule exactly as directed. Set reminders, if needed, to be sure your dog receives their medication consistently. If diet is a contributing factor, work with your veterinarian to provide the best nutrition for your dog. 

Monitor symptoms

Keep a close eye on your dog’s behavior and overall health. Watch for signs of improvement or worsening symptoms, such as changes in appetite, energy levels, or coat condition. If you notice any changes, check in with your vet, who may need to adjust their treatment plan.

Schedule regular vet visits

Consistent veterinary checkups are key to monitoring your dog’s thyroid hormone levels and overall health. Your vet will likely recommend regular blood tests to determine if their treatment is working effectively, and make any necessary adjustments.

Be prepared for lifelong management

Hyperthyroidism often requires ongoing treatment and regular monitoring, which means more frequent vet visits and additional costs. Consider whether you have the time, patience, and financial resources to care for a dog with a medical condition like hyperthyroidism.

If you’re able to provide the necessary care, that’s fantastic. While it might feel overwhelming at first, establishing a routine will make managing their needs easier — and seeing the dog thrive under your care can be very fulfilling.

Commonly asked questions

Should I adopt a senior dog? 

Adopting a senior dog is an excellent choice for those looking for calmer pets, who are more responsive to basic commands and have established personalities. Though they may require additional care for conditions like hyperthyroidism, they can still lead happy, fulfilling lives with the right support.

Is there a vaccine for hyperthyroidism in dogs? 

No, there’s no vaccine for hyperthyroidism in dogs. Vaccines generally protect against infectious diseases caused by viruses or bacteria, whereas hyperthyroidism is a hormonal disorder.

What is the life expectancy for dogs with hyperthyroidism?

A dog with hyperthyroidism caused by a thyroid tumor may live up to three years following treatment, depending on the characteristics of the cancer. For hyperthyroidism caused by overmedication or diet, life expectancy is typically normal once the underlying issue is addressed.

Are dogs with hyperthyroidism aggressive?

Hyperthyroidism may cause hyperactivity or restlessness, but aggressive behavior is rare. Proper treatment can prevent behavioral changes and keep your dog calm and comfortable.

Resources 

Disorders of the Thyroid Gland in Dogs  

Hyperthyroidism

Hyperthyroidism in Dogs: Symptoms, Causes, and Treatments