This article discusses the results of investigations of age-related involution in the coxofemoral joint (CFJ) cartilage in domestic cats (C) from the age of six months to thirty years. Forty whole CFJ samples were used as specimens for complete morphofunctional analysis. The methods of anatomical section, X-ray, light and polarizing optical microscopy of histological microslides stained with hematoxylin-eosin, and Sirius Red F3B, as well as morphometry were used in conducting this comparative analysis. This investigation into the peculiarities of joint cartilage (JC) cell structure in cats showed that prominent change in the CFJ is related to age, sex and weight of the animal. Morphological changes in the JC are compensatory at first, and only significantly later do they become pathological. It was observed that a decrease in the thickness of the JC, its erosion and micro-fractures of the subchondral bone are the morphological correlation to the exhaustion of adaptation-compensatory mechanisms due to unfavorable internal and external factors. Our investigation allows for a deeper understanding of the biology of cartilage and the mechanisms of its pathological changes, and further indicates a rational path to their prevention and cure.