What is Rimadyl? Rimadyl is a non-steroidal anti-inflammatory drug (NSAID) designed to treat arthritis. Rimadyl provides safe and effective relief of pain and inflammation due to canine arthritis, orthopedic and soft tissue surgery. Rimadyl for dogs works for 24 hours and come in liver flavored chewable tablets. Rimadyl medication should not be used in any dog with kidney, liver, or heart disease. Do not give to dogs that are pregnant or nursing. Read more about Rimadyl and it’s side effects.