Canine osteoarthritis (OA) is a complex chronic condition involving deterioration and inflammation of joint structures, leading to pain and decreased mobility. There are several oral and injectable nonsteroidal anti-inflammatory drugs (NSAIDs), such as meloxicam, that are approved for the treatment of canine OA. These forms of administration, however, pose several challenges, including owner compliance and adverse systemic effects. The purpose of this study is to evaluate an innovative plant-based transdermal delivery system for the application of topically applied meloxicam. It is hypothesized that this delivery system will carry meloxicam to the synovial cavity of study dogs at levels greater than those achieved by standard oral meloxicam administration. 3 male and 3 female eligible research dogs, 20-40kg at 6-24 months of age, are enrolled in this 2-phase randomized crossover study. In phase 1, dogs are randomized to oral or transdermal treatment, and left or right stifle. In phase 2, following a 21-day washout, the dogs are crossed over. The oral meloxicam group receives a loading dose of 0.2mg/kg on Day 1 followed by 0.1mg/kg q24h for another 5 days. The transdermal meloxicam group receives a 1mg/kg dose q24h for 6 days. Plasma, urine, synovial fluid and skin biopsy samples are collected before dosing and 8 hours post last dosing in each phase of the study. Plasma and urine results indicate no adverse effects with oral or transdermal meloxicam treatment. Analyses of samples for meloxicam levels using mass spectroscopy as well as biopsy histopathology and synovial fluid cytologic analyses are in progress.