What is Hypothyroidism?

Hypothyroidism is a common hormonal disorder in dogs, and less commonly diagnosed in cats. It occurs when the thyroid glands do not produce enough thyroid hormone, which is responsible for regulating metabolism.

In dogs, hypothyroidism most often affects middle-aged, medium to large breeds. Common signs include:

• Lethargy

• Weight gain despite no increase in appetite

• Thinning hair coat, hair loss

• Recurrent skin infections

• Intolerance to cold

Some dogs may also show behavioural changes such as:

• Reduced activity

• Mental dullness

Diagnosis involves a veterinary examination and blood testing to measure thyroid hormone levels. Because other illnesses can mimic hypothyroidism, careful interpretation of results is important.

Treatment is straightforward and highly effective. Affected dogs are prescribed a daily thyroid hormone replacement tablet (Forthyron). Most pets show improved energy within a few weeks, while skin and coat changes may take several months to resolve. Regular blood tests are required to monitor levels and ensure the correct dose.

With appropriate treatment and monitoring, dogs with hypothyroidism typically go on to live normal, healthy lives.