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, the brain, and metabolism.

Gene name

TPO

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. There may be 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

, r, , Tenterfield Terrier,

Citations

Dodgson SE, Day R, Fyfe JC. Congenital hypothyroidism with goiter in Tenterfield terriers. J Vet Intern Med. 2012 Nov-Dec;26(6):1350-7. doi: 10.1111/j.1939-1676.2012.01015.x. Epub 2012 Nov 1. PMID: 23113744. Bellumori TP, Famula TR, Bannasch DL, Belanger JM, Oberbauer AM. Prevalence of inherited disorders among mixed-breed and purebred dogs: 27,254 cases (1995-2010). J Am Vet Med Assoc. 2013 Jun 1;242(11):1549-55. doi: 10.2460/javma.242.11.1549. PMID: 23683021. Major S, Pettigrew RW, Fyfe JC. Molecular Genetic Characterization of Thyroid Dyshormonogenesis in a French Bulldog. J Vet Intern Med. 2015 Nov-Dec;29(6):1534-40. doi: 10.1111/jvim.13651. Epub 2015 Oct 18. PMID: 26478542; PMCID: PMC4895686. Fyfe JC, Kampschmidt K, Dang V, Poteet BA, He Q, Lowrie C, Graham PA, Fetro VM. Congenital hypothyroidism with goiter in toy fox terriers. J Vet Intern Med. 2003 Jan-Feb;17(1):50-7. doi: 10.1892/0891-6640(2003)017<0050:chwgit>2.3.co;2. PMID: 12564727.

Disclaimer

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