Vitamin D-Deficiency Rickets (VDR)

Hereditary Vitamin D - Resistant Rickets is a metabolic bone disease in both humans and animals that results in softening, bending and weakening of the bones – rickets. Affected dogs with this hereditary disorder show insufficient intestinal absorption of calcium needed for the growth of skeleton because of vitamin D deficiency or decreased vitamin D activity. The condition is caused by defects in the vitamin D receptor gene that lead to inhibition of bone mineralization. First symptoms usually appear around 4 months of age, when dogs easily get tired during everyday tasks. Later, spontaneous fractures, bone and limb deformities, alopecia and other clinical signs can occur (hypocalcemia, secondary hyperparathyroidism, joint pain, lameness). This disorder often results in euthanasia due to frequent bone fractures.

Inheritance: autosomal recessive

Mutation: VDR gene

Genetic test: The method used for genetic testing is extremely accurate and allows complete differentiation between affected animals, carriers and healthy dogs. DNA testing can be done at any age.