Methods and compositions for treating symptoms of conditions such as but not limited to osteoarthritis and rheumatoid arthritis in canines. The methods may feature direct intraarticular injection of a recombinant self-complementary adeno-associated virus (sc-rAAV) with a vector adapted to express a modified IL-1Ra peptide. The methods of the present invention may express a therapeutically effective amount of the modified IL-1Ra peptide so as to ameliorating symptoms associated with the condition being treated.