Dogs have a thyroid gland in their neck that produces hormones. When excess thyroid hormones are released, hyperthyroidism occurs and causes negative effects on the body. This condition is most common in older dogs but it’s quite rare overall.
Causes of Hyperthyroidism in Dogs
A cancerous Thyroid mass is the most common cause of hyperthyroidism in dogs. More rarely, a benign mass called an adenoma may develop in the thyroid gland and cause symptoms.
Giving too much levothyroxine to a hypothyroid dog is also a common cause of hyperthyroidism. This can be avoided through monitoring and dose adjustments.
Signs of Hyperthyroidism in Dogs
Hyperthyroidism in dogs causes various symptoms, including:
- Enlargement of the thyroid gland
- Weight loss despite increased appetite
- Increased thirst and urination
- Increased heart rate
- Abnormal heart rhythms
- Dull coat
- Hair loss
- Hyperactivity
- Vomiting
- Diarrhea
- Changes in behavior, such as assault
- Difficulty breathing and swallowing
- To cough
- Facial swelling
If you notice any of these symptoms, take your dog to the veterinarian immediately to determine the underlying cause and begin treatment.
Management of Hyperthyroidism in Dogs
Management depends on the underlying cause. For dogs who have received too much levothyroxine, a simple dose adjustment can return thyroid hormone levels to normal.
In dogs with thyroid masses, surgery may be an option. Radiation therapy can be used alone or in combination with surgery as another form of treatment. Radioactive iodine therapy also destroys thyroid tissue and reduces hormone levels. Your veterinarian can advise you on the best approach based on your dog’s overall health and needs.
Complications of Hyperthyroidism in Dogs
Dogs with hyperthyroidism are at increased risk of developing other health problems, such as heart or kidney disease and high blood pressure. Because the thyroid cancer has usually spread by the time of diagnosis, most dogs experience a shortened lifespan. However, with proper management, dogs with hyperthyroidism can still live happy lives.