Dr. Kent Allen wrote a paper for the United States Equine Federation (USEF) about drug use in horses and today on Texas Vet News I am going to share some of his thoughts.  There are many medications available for horses and although many are quite safe, others can have severe side effects.  The recent event that occurred in Florida with compounded medication leading to death of polo horses should remind everyone that medications are not without side effects.  We need to realize that horses cannot tell us where it hurts and also cannot tell us how they feel while taking certain medications. 

The USEF has had a medication rule for 30 years that has been modified as needed. The last modification was in 1998, and it set dosage restrictions on permitted medications.  However, a proposal to limit non-steroidal antiinflammatory drugs, or NSAIDs, did not pass.  Since that time, the American Quarter Horse Association has adopted the one NSAID rule.  NSAIDs are the most commonly used medication in athletic horses, and examples are phenylbutazone (called bute) and banamine.  These drugs are effective in treating inflamed joints and soft tissues as well as colic.  And although these drugs are very useful, side effects such as gastric or colon ulcers can occur and possibly lead to death.  Also, more than one NSAID should never be used at the same time; this is called stacking and it can increase the chance of toxicity.  I hear owners indicate they gave their horse bute and banamine at the same time, but this should never be done.  It was never intended for more than one NSAID to be given at the same time as another as the toxicity is greater and both are not any more effective than one drug alone.