Previcox is a palatable tablet in two sizes. The active ingredient is Firocoxib. This is a NSAID (Non- steroidal anti-inflammatory drug.) It is amongst the most modern of the NSAID’s. It is only used in dogs for the relief of pain and inflammation especially in musculo-skeletal cases (arthritis, myositis, sprains and strains etc) and is it a very useful drug. Like all NSAID’s it can rarely irritate the stomach and or intestines even to the extent of causing bleeding. Any vomiting or passing of blood should cause you to stop administering Previcox and let us know urgently.