Hypothyroidism is a common hormonal disorder in dogs, characterized by a low-performing thyroid gland. The thyroid gland produces hormones that regulate growth, development, metabolism, digestive function and bone maintenance. When there is an underactive thyroid, some of these functions are affected leading to a range of symptoms.

Symptoms of Hypothyroidism

  • Weight Gain: Dogs with hypothyroidism often gain weight and might get obese despite a reduced appetite.
  • Lethargy: Dogs with thyroid disease are always low on energy Affected dogs may appear sluggish and lack energy.
  • Skin Issues: Dry, flaky skin, and dull hair coat with a bilaterally symmetric hair loss are common signs.
  • Intolerance to Cold: They are more sensitive to cold and are unable to manage Dogs with hypothyroidism may become more sensitive to cold temperatures.
  • Muscle Weakness: Muscle weakness can result in exercise intolerance.
  • Behavioural Changes: Some dogs may exhibit changes in behaviour, including depression or aggression.

Causes of Hypothyroidism

Hypothyroidism in dogs is primarily caused by the immune system attacking and damaging the thyroid gland. In some cases, it can also be due to congenital issues or medication side effects.


Treatment typically involves daily thyroid hormone supplementation in the form of medication. Your veterinarian will determine the appropriate dosage based on your dog’s specific needs. Regular blood tests will monitor thyroid hormone levels to ensure proper management.

Your veterinarian will also recommend some dietary adjustments. Although there is no cure for hypothyroidism, with proper treatment, most dogs can lead healthy and active lives. If you notice any symptoms of hypothyroidism in your dog, consult your veterinarian for a thorough evaluation and treatment plan. Early diagnosis and intervention can greatly improve your dog’s quality of life.