Congenital hypothyroidism with dwarfism (CH)

Hypothyroidism is a condition in which the thyroid gland does not produce enough hormones. These hormones regulate numerous metabolic processes and are particularly important for normal growth and development.

In Rottweilers, a genetic variant in the TG gene has been identified that causes an inherited form of hypothyroidism. Affected puppies are smaller and lighter than their littermates and exhibit disproportionate dwarfism. Common clinical signs also include limb deformities, a shortened tail, unusually thick skin, developmental delay, and pain during movement. Unlike other forms of hypothyroidism, this variant is generally not associated with goitre formation.

The TG gene encodes the protein thyroglobulin, which is required for the production of the thyroid hormones T3 and T4. When this gene is altered, insufficient amounts of thyroid hormones can be produced. Treatment with thyroid hormone replacement therapy may partially alleviate the clinical signs but is usually unable to prevent them completely.

The genetic test can identify dogs that carry this genetic variant. This supports responsible breeding decisions and helps prevent the birth of affected puppies as well as the further spread of the variant.