Hypothyroidism in Dogs
What is Hypothyroidism?
The Thyroid is a small gland that sits in the neck of your dog and usually is so small it cannot be palpated. The thyroid gland’s activity is regulated by the pituitary, which sits at the base of the brain. The role of the thyroid is to produce a hormone that helps to control metabolism. The other roles of thyroid hormone are to assist with mental alertness, nerve function and skin and coat quality.
An underactive thyroid or hypothyroidism is an under diagnosed condition that occurs in middle aged to older dogs. The reason it is often under diagnosed is because the signs can be very subtle and are often easily confused with the normal signs of aging.
The signs you may see if your dog suffers hypothyroidism are related to:
- Slowing of metabolism ie weight gain without necessarily eating more, tiredness and reluctance to exercise
- Changes to the skin and coat such as dryness, excess shedding and hair thinning and increased pigmentation to the skin
- Neurological changes mainly showing as lack of alertness or dullness but in severe cases can show profound weakness with slowed heart rate and low blood pressure.
In 95% of patients the cause of hypothyroidism is due to asymptomatic damage to the thyroid gland itself. The reason for this is often not known but fortunately diagnosis and treatment is very easy.
Diagnosis involves a blood test that measures thyroid hormone (Total T4) and sometimes we need to check the level of hormone the pituitary produces to stimulate the thyroid (TSH).
Treatment involves thyroid hormone supplementation that is taken daily for the rest of your pet’s life. Changes in your dog’s activity and alertness should improve after 4 weeks of treatment and changes in hair coat and quality may take 8 weeks.