Practicing veterinarians around the United States were asked to participate in a Previcox (firocoxib, Merial) Experience Trial (PET). Firocoxib is a cyclooxygenase (COX)-2-selective, COX-1-sparing nonsteroidal antiinflammatory drug (NSAID) developed for veterinary use. The objective of this study was to familiarize veterinarians with firocoxib for the relief of the inflammation and pain of canine osteoarthritis (OA). Dogs with OA were enrolled, and their owners were instructed to maintain a daily diary. They were asked to return 7 to 10 days after treatment was begun and again after 40 days of treatment. At the initial visit, blood was drawn for serum chemistry and hematology analysis. A 10-day supply of firocoxib and the diaries were given to the owners. After the blood was analyzed, if a patient was still eligible it began the study. If the dog was currently on NSAIDs, a washout period was required. A total of 1002 dogs from 106 sites in 36 states were enrolled. Of these, 954 returned for the 10-day evaluation and 864 returned for the 40-day evaluation. Of the 1002 dogs, 458 (46%) had previously been treated with at least one NSAID. Only 2.9% of the dogs were withdrawn because of gastrointestinal side effects, and no serious drug-related events were reported. Improvement was noted at the first postenrollment period. By the end of the 40-day period, investigators and owners both considered the dogs to have improved (93% and 91%, respectively), and 86% of the owners believed that their dogs were happier and more active after treatment. Study funded by Merial Limited

COMMENTARY: There are several NSAIDs from which veterinarians can choose to treat patients with OA. The data yielded from this large field trial showed that firocoxib was safe and effective for relieving canine OA-related inflammation and pain. This drug will be a good addition to a clinic's pharmacy.

Clinical effectiveness and safety of a new NSAID, firocoxib: A 1,000 dog study. Ryan WG, Moldave K, Carithers D. VET THER 7:119-126, 2006.