Bute is short for phenylbutazone, which is a non-steroidal anti-inflammatory (NSAID) prescription medication used to treat inflammatory conditions associated with the musculoskeletal system in horses. It is a potent drug that is frequently used to relieve pain associated with musculoskeletal disorders such as arthritis. Bute comes in many different formulations, including tablets, injectable, powder, and paste. It is important to consult with a veterinarian before administering Bute to a horse, as this drug can mask signs of more serious problems. Bute is generally well tolerated in horses, but prolonged administration of Bute can cause gastrointestinal disorders such as ulcers, colitis, and kidney problems. Toxic effects are most commonly seen with continued administration of high doses over an extended period of time, but some horses are especially sensitive and should be monitored very closely while on Bute. The most serious side effect of Bute is a condition called right dorsal colitis, which is inflammation of the colon on the horses upper right side. Bute is the most commonly used anti-inflammatory in veterinary medicine and is available from a veterinarian in multiple forms. It is recommended to consider other, safer methods to help control pain or joint discomfort instead of administering Bute long-term. Alternatives to giving horses Bute long-term include joint injections, intramuscular injections, hyaluronic acid products, and biologic or regenerative therapies. Some non-prescription ingredients commonly included in joint supplement formulas may also help manage the discomfort associated with joint problems.