Osteoarthritis is a significant source of chronic pain in cats. What is Feline Osteoarthritis (OA)? Osteoarthritis (OA), or degenerative joint disease, is a painful, progressive condition characterized by the gradual breakdown of joint cartilage and underlying bone. With cartilage loss the bones will rub against each other further damaging the joint causing pain, inflammation, swelling, decreased flexibility and other changes. It cannot be cured. However, you can slow it d