Congenital Hypothyroidism

Congenitally hypothyroid pups are usually lethargic and overweight with a characteristic "tragic" facial expression due to increased water retention in the facial folds. They may also present with dwarfism of the long bones and spine as well as delayed mental development. Abdominal hair loss, as well as a characteristic goiter, which is actually an enlarged thyroid gland attempting to produce thyroxine (to no avail), are also common.

Signs first develop in puppyhood and continue throughout their lives if untreated.

Genetic and laboratory testing along with clinical signs are used to diagnose this disease.

Hypothyroidism is a lifetime condition and can be managed medically with thyroxine supplementation. If untreated, dogs can enter a rare condition known as myxedema coma, where lethargy can progress to a comatose state and have a reduced heart rate, breathing rate, and low body temperature. This is an emergency situation that requires intensive care.

Talk to your vet about your dog’s congenital hypothyroidism result, as it may influence how they monitor your dog’s thyroid function, growth, and development.

Schedule regular checkups and bloodwork to check thyroid hormone levels and make sure your dog is growing normally.

Contact your vet if you notice signs such as sluggishness, weight gain, hair loss, or changes in coat quality, as early treatment can help your dog stay healthy and active.

This mutation was first described in Tenterfield Terriers.

Penetrance: This disease is inherited in an autosomal recessive manner, meaning that a dog must have two copies of the mutation to be affected.

Gene

TPO

Inheritance type

recessive

Clinical category

Endocrine

Citations

1. Dodgson et al 2012

• Tenterfield Terrier