Breeds Affected: Spanish Water Dog (Test # D106), Rat and Fox Terriers (Test # D107), Tenterfield Terrier (Test # D108).

Samples Accepted: Blood, Buccal Swabs

Disease Information: Congenital Hypothyroidism is also known as Congenital Hypothyroidism with Goiter. Affected pups are exhibit growth retardation, delayed tooth eruption, delayed eye and ear opening, lethargy, hair coat abnormalities, thickened skin, and goiter. The disease can be fatal without early diagnosis and treatment.

Test Information: There are three different mutations responsible for Congenital Hypothyroidism in the dog. Hypothyroidism in all three breeds is autosomal recessive, meaning that animals with two copies of the mutated allele are affected with hypothyroidism, and animals with one copies are clinically-normal carriers.

Spanish Water Dog:Test # D106: This mutation test identifies a single base pair insertion in exon 1 of the TPO gene.

Fyfe, J.C., Lynch, M., Olsen, J., Louёr, E. : A thyroid peroxidase (TPO) mutation in dogs reveals a canid-specific gene structure. Mamm Genome 24:127-33, 2013. Pubmed reference: 23223904. DOI: 10.1007/s00335-012-9442-y.

Toy Fox Terriers, Rat Terriers: Test # D107: This mutation test identifies a single base pair change in the TPO gene.

Fyfe, J.C., Kampschmidt, K., Dang, V., Poteet, B.A., He, Q., Lowrie, C., Graham, P.A., Fetro, V.M. : Congenital hypothyroidism with goiter in toy fox terriers Journal of Veterinary Internal Medicine 17:50-7, 2003. Pubmed reference: 12564727.

Pettigrew, R., Fyfe, J.C., Gregory, B.L., Lipsitz, D., Delahunta, A., Summers, B.A., Shelton, G.D.: CNA hypomyelination in Rat Terrier dogs with congenital goiter and a mutation in the thyroid peroxidase gene. Vet Pathol 44:50-6. Pubmed reference: 17197623. DOI: 10.1354/vp.44-1-50.

Tenterfield Terriers: Test # D108: This mutation test identifies a single base pair change in the TPO gene.

Dodgson, S.E., Day, R., Fyfe, J.C.: Congenital hypothyroidism with goiter in Tenterfield terriers. J Vet Intern Med 26:1350-7, 2012. Pubmed reference: 23113744.
DOI: 10.1111/j.1939-1676.2012.01015.x.

Further information is available at the Online Mendelian Inheritance in Animals website.