Rimadyl is a non-steroidal anti-inflammatory (NSAID) used to treat pain and inflammation due to arthritis and other joint diseases, including hip dysplasia. It's also used to reduce pain associated with surgery or dental procedures, as well as to reduce fever. Rimadyl works by reducing hormones that cause pain and inflammation in the body. Rimadyl may also be used for purposes other than those listed here. Rimadyl requires a prescription from your veterinarian.