Mavacoxib (trade name Trocoxil) is a veterinary drug used to treat pain and inflammation in dogs with the degenerative joint disease. Mavacoxib is a non-steroidal anti-inflammatory drug (NSAID) of the coxib class. Mavacoxib acts by preferential inhibition of COX-2-mediated prostaglandin synthesis. It, therefore, possesses analgesic and anti-inflammatory properties. The products of COX-2 metabolism are also involved in ovulation, implantation, and closure of the ductus arteriosus. Mavacoxib is well absorbed after oral administration; bioavailability was 87% in fed dogs and 46 % in fasted conditions and the recommended dose is based on administration with food. Therapeutic concentrations in fed dogs are reached rapidly and peak concentrations are obtained in less than 24 hours after administering a dose. Mavacoxib is approximately 98% bound to plasma proteins. It is extensively distributed throughout the body and almost all the mavacoxib-related residues in plasma comprise parent drug. The rate of body clearance of mavacoxib is slow and the major route of elimination is by biliary excretion of the parent drug. Adverse reactions of the digestive tract such as vomiting and diarrhea were commonly reported, loss of appetite, hemorrhagic diarrhea, and melaena have been reported in uncommon cases. Gastrointestinal ulceration was reported in rare cases. Apathy, degradation of renal biochemistry parameters and impaired renal function have been reported in uncommon cases. In rare cases, these adverse reactions may be fatal.