NSAIDs are the most widely used analgesics in veterinary medicine, and all have some toxic potential. The most common adverse class effects are gastrointestinal, renal, hepatic, and coagulation disorders. When treating chronic pain associated with osteoarthritis, the effectiveness of NSAIDs can be enhanced by physical therapy, use of chondroprotective agents, certain adjunctive drugs, and diet and exercise to control weight. To treat acute perioperative pain, NSAIDs are more effective when used preemptively, in the context of balanced (multimodal) analgesia, and in well-hydrated patients with normal blood pressure and renal function. Screening and monitoring to identify high-risk candidates for NSAID treatment should include a physical examination and patient history, identification of preexisting diseases or conditions, obtaining baseline and periodic hematologic and clinical chemistry values, and ensuring that other NSAIDs or contraindicated drugs are not used concurrently. When switching a patient from one NSAID to another (when no side effects have been seen), a washout period of 5 to 7 days minimizes chances for adverse drug interactions. Informing clients of the potential adverse effects of NSAID therapy and signs of NSAID toxicity greatly increases the likelihood of safe use of this class of drugs.