Prostaglandins that are present in dogs promote inflammation and pain. NSAIDs reduce the production of these prostaglandins by inhibiting COX enzymes. Having fewer prostaglandins by either blocking some activity of certain prostaglandins or by completely blocking COX enzymes, NSAIDs reduce inflammation and ongoing pain in dogs. But unfortunately, NSAIDs can cause side effects as they interfere with the other positive functions of prostaglandins.