Description: A genetic condition that causes a deficiency in the production of the enzyme Thyroid Peroxidase (TPO) which is important for the normal metabolism and development of the body. Puppies born with this inherited condition may die in a few weeks. They can easily be distinguished from the rest of the litter because it is not as active as the others and its head may look larger compared to the rest of the body. Its neck may show signs of swelling which can be easily palpable. They may also have an abnormally slow growth and development in the bones of the legs, face, and spine. A correct diagnosis is often achieved with a DNA test.

Breeds Commonly Affected: Toy Fox Terrier