Disease overview

Congenital hypothyroidism is an inherited condition in which the thyroid does not produce the hormone Thyroxine, also known as T4. This is due to the mutation in a gene that leads to dysfunctional binding of iodide, which is a necessary step in creating thyroid hormone. This hormone has various roles and is important for the skeletal system, brain, and metabolism.

Gene name

SLC5A5

Inheritance

Autosomal recessive

Signs and symptoms

Dogs affected with congenital hypothyroidism present with signs at a young age. These include lethargy, weight gain, and a "tragic" facial expression. There may be skeletal abnormalities that lead to dwarfism. Hair loss may be evident. They may have an enlarged goiter (thyroid gland).

How is it diagnosed

A veterinarian will conduct a thorough exam, including a review of health history and any clinical signs. Tests that evaluate hormone levels produced by the thyroid will lead to a definitive diagnosis. Genetic testing is necessary to determine if there is an underlying genetic cause, which can assist veterinarians with diagnosis and help breeders identify affected and carrier dogs.

Breeds at higher risk

Citations

Soler Arias EA, Castillo VA, Garcia JD, Fyfe JC. Congenital dyshormonogenic hypothyroidism with goiter caused by a sodium/iodide symporter (SLC5A5) mutation in a family of Shih-Tzu dogs. Domest Anim Endocrinol. 2018 Oct;65:1-8. doi: 10.1016/j.domaniend.2018.04.005. Epub 2018 Apr 24. PMID: 29777899.

Disclaimer

Disease diagnosis and treatment should always be performed by a veterinarian. The following information is for educational purposes only.