The Dangers Of Over-Medication And Under-Diagnosis

In his introductory Between Rounds, our new columnist discusses one of the primary problems in the sport horse world today.

In this day and age, there are many medications available to humans and horses. While some of these medications are quite benign, most of them have varying degrees of side effects. Some of the side effects are relatively minor, while some are rapidly fatal.

Recent national events, such as the deaths of 21 polo ponies in April, have shown us that we must take great care in what we put in our horses.

Obviously, horses can neither tell you where it hurts nor can they tell you what they feel like on a given medication. So, paying attention to what our horses have been diagnosed and medicated with is critical.

The U.S. Equestrian Federation equine drug and medication rule is a rule that has evolved for 30-plus years and serves almost 30 breed and discipline organizations. It is, however, a rule that has served us well for a long time,
as long as we remember to continually modify it in favor of the horse.

The last major modification of the rule was in 1998. The modification involved setting dosage restrictions on all of the medications restricted by the USEF. This mission was accomplished and has since helped people with correctly medicating their horses.

Another proposal that was put forward at the same meeting was not able to be passed at that time. The USEF Veterinary Committee put forward a recommendation that the non-steroidal anti-inflammatory drugs be limited to a single medication. This proposal was ahead of its time and had neither the research nor the political will to succeed.

Since that time the American Quarter Horse Association has adopted a single NSAID rule and has lived with it successfully for many years. It’s certainly time to revisit this proposal within the USEF.

NSAIDs (phenylbutazone, Banamine, Equioxx and others) are the most commonly used medications in the athletic horse. These medications provide us with the ability to treat inflamed joints, readily and easily. They’re useful in treating colic conditions. They are the single most useful medication in temporarily treating mild inflammatory conditions in the horse.

Similar to the NSAIDs available for human usage, they are meant to be taken at reasonable doses for a short period of time. Complications of overmedication can occur when they’re taken at too high a dose, too long a period of time, or combined with other medications.

The complications of over-medication in the horse include gastric ulcers, deterioration of joints and tendons from masking pain and rupture of the intestine. No single NSAID licensed for use in the horse was ever intended to be used in conjunction with another NSAID.

The research in the past 10 years into NSAID use and pain management has taught us much. We are now aware of the very real danger of masking significant injury in our performance horses with more than one NSAID drug. We are aware that “stacking” NSAID use in some circumstances is similar to doubling the dose. We are aware in the stressed horse even normal doses can cause significant side effects. We are aware of how common gastrointestinal side effects (gastric ulcers, colic, intestinal perforation) are with a single nonsteroidal at elevated doses. We are aware that it is difficult to predict the effect on the horse in combining two non-steroidal drugs.