Rickets is a classic metabolic bone disease of humans and animals. In dogs and cats the disease is quite rare. However, the ability to distinguish it from other similar symptoms is an important task for any veterinarian. The pathology of rickets is based on a violation in the phosphorus-calcium metabolism, associated with a violation of the metabolism of vitamin D. Most often there is a food form of rickets, caused by a lack of dietary vitamin D. However, both in cats and dogs there are genetic forms of the disease, in which the body is not able to synthesize certain proteins that take part in any of the stages of metabolism of this vitamin. Most often food form of suffer puppies until 6 months and kittens in age about 4 months. Any breed predisposition in cats is not revealed. In dogs rickets is exposed to fast-growing breeds such as gazehounds (greyhounds, Russian wolfhound), Shetland Sheepdog, Rhodesian Ridgeback, Dogo Argentino, Pomeranian dog described in the literature more often than other breeds. Rickets are diagnosed by x-ray analysis, blood tests for the concentration of vitamin D and animal history data. Treatment of food rickets is the appointment of a corrective diet. Animals with genetic rickets are prescribed calcitriol for life.