Thyroid Care

Hypothyroidism in Dogs

Hypothyroidism occurs when the thyroid gland doesn't produce enough thyroid hormone. It's the most common hormonal disorder in dogs, typically affecting middle-aged and older dogs. Certain breeds, including Golden Retrievers, Dobermans, Irish Setters, and Dachshunds, are more prone to the condition.

When thyroid hormone levels are low, metabolism slows down. Dogs with hypothyroidism often gain weight despite eating normally, become lethargic and less interested in exercise, develop dry or thinning coats, experience recurring skin infections, seek out warm places, and may have a slow heart rate. The symptoms develop gradually and are sometimes mistaken for normal aging.

Hyperthyroidism in Cats

Hyperthyroidism is the opposite problem: the thyroid gland produces too much hormone. It's the most common hormonal disorder in cats, typically affecting older cats. The excess hormone accelerates metabolism, causing the body to burn energy too quickly.

Cats with hyperthyroidism often lose weight despite eating more than usual, become restless or hyperactive, drink and urinate excessively, may have vomiting or diarrhea, and sometimes develop a rapid heart rate or heart murmur. Without treatment, hyperthyroidism can lead to serious complications, including heart disease, high blood pressure, and kidney damage.

How is thyroid disease diagnosed? 

A blood test measures thyroid hormone levels. Dogs are tested for T4, with additional hormones checked if results are borderline. Cats are tested for T4, often alongside kidney function and blood pressure. Results are often available the same day.

What are the signs my dog might have hypothyroidism? 

Common signs include weight gain, low energy, hair loss or thinning coat, dry or flaky skin, recurring skin or ear infections, and seeking out warm spots. Symptoms develop gradually and may be subtle at first.

What are the signs my cat might have hyperthyroidism? 

Common signs include weight loss despite a strong appetite, restlessness, increased thirst and urination, vomiting or diarrhea, an unkempt coat, and sometimes a lump in the neck. Some cats become more vocal or irritable. Thyroid testing is recommended for senior cats showing these changes.

Is thyroid disease treatable? 

Yes. Both hypothyroidism and hyperthyroidism are highly manageable. Most pets return to normal energy, a healthy weight, and a good quality of life once hormone levels are regulated.

How is hypothyroidism in dogs treated? 

Dogs take a daily thyroid hormone replacement, given once or twice a day for life. The medication is affordable and well-tolerated. Most dogs improve within a few weeks.

How is hyperthyroidism in cats treated? 

Options include daily medication, prescription diets for mild cases, radioactive iodine therapy for a permanent cure, or surgery. Treatment depends on the cat's age, health, and severity of the condition.

How often will my pet need blood tests? 

Thyroid levels are rechecked 4 to 6 weeks after starting treatment, with dose adjustments as needed. Once stable, most pets need rechecks every 6 to 12 months. Cats with hyperthyroidism may also need periodic kidney and blood pressure monitoring.

Are there side effects from thyroid medication? 

Most pets tolerate it well. Dogs on replacement therapy rarely have issues. Cats on anti-thyroid medication may occasionally experience vomiting, appetite loss, or skin reactions. Treatment can be adjusted if side effects occur.

Can thyroid disease be prevented? 

No. There is no known way to prevent thyroid disease, but routine wellness bloodwork allows for early detection before symptoms develop, which is especially important for senior pets.

My pet was diagnosed with thyroid disease. What's their prognosis?

The prognosis is excellent in most cases. With consistent treatment and regular monitoring, most pets with thyroid disease live normal, comfortable lives with no reduction in life expectancy.