Congenital Hypothyroidism with Goiter (Spanish Water Dog Type)

General Information: Congenital Hypothyroidism with Goiter (CHG) in Spanish Water Dogs is an inherited condition that results in the deficiency of a crucial enzyme necessary for proper thyroid function and hormone production. This hormone is vital for the normal development and metabolism of dogs. Affected puppies typically show signs around two weeks of age, including reduced movement and being noticeably smaller compared to their littermates. They often develop visible goiters, presenting as swellings in the neck due to enlarged thyroid glands. Physical characteristics include dwarfism with short legs, large heads, and fluffy coats that lack the usual guard hairs. The disease also leads to various neurological and neuromuscular deficits, which can result in failure to thrive and premature death if left untreated. Early diagnosis and treatment with thyroid hormone can prevent or reverse many of the symptoms; however, the thyroid glands may continue to enlarge over time, potentially causing airway obstruction despite treatment.

How to Read Your Dog's Test Results for this Genetic Variant:

Two Variants Detected: Dog Likely Affected

One Variant Detected: Dog Unlikely Affected

No Variants Detected: No Effect

Gene / Testing Information: Genetic testing for the TPO gene is crucial for identifying carriers of the mutation responsible for Congenital Hypothyroidism with Goiter (CHG) in Spanish Water Dogs. This condition is inherited in an autosomal recessive manner, meaning a dog must inherit two copies of the mutated gene, one from each parent, to develop the disease. Dogs carrying only one copy of the mutation (carriers) typically do not show symptoms but can pass the gene to their offspring. When two carriers are bred, each puppy has a 25% chance of developing CHG and a 50% chance of being a carrier. Reliable genetic testing is essential for responsible breeding practices to avoid mating two carriers, thereby reducing the risk of producing affected puppies. By ensuring that only non-carrier dogs are bred, breeders can help eliminate this severe thyroid condition from Spanish Water Dog populations, promoting healthier future generations and maintaining the integrity and health of their breeding lines.