Intra-articular use of analgesic/antinflammatory drugs in dogs and horses

Joint pain is a major cause of lameness in animals such as horses and dogs, and it may affect their athletic performance and quality of life. The intra-articular administration of analgesic/antinflammatory drugs is a common practice in veterinary medicine, for both lameness diagnosis and joint pain management. It is used either perioperatively, such as in animals undergoing arthroscopy/arthrotomy, and in osteoarthritic animals. However, evidence regarding efficacy and safety of each drug is limited, and controversies persist in these areas. In particular, it is often uncertain whether a defined treatment is effective by simply relieving the symptomatic pain associated with the joint disease, or whether it has a positive effect on the joint environment. Moreover, there is still much hesitation about treatments for joint diseases, related to the time of their application for the best outcome, and to any possible deleterious side effects. This article includes a review of the literature concerning the main analgesic/antinflammatory drugs used intra-articularly for managing acute and chronic joint pain/inflammation in dogs and horses. Three main issues for each class of drugs are considered, including clinical efficacy, pharmacokinetics, and local cytotoxic effects.