Equine antimicrobial resistance still debatable

Equine antimicrobial resistance still debatable

Feb 01, 2003

Equine practitioners may still take the backseat to food animal practitioners in the debate over antimicrobial resistance, but their input may help sustain prudent use of controversial drugs for all species.

"Practitioners have a major responsibility in ensuring the continued effectiveness of antimicrobials, which are vitally important in the treatment of infectious disease in equine patients," says Dr. Josie Traub-Dargatz, lead author of a paper on "Antimicrobial Resistance - What's the Big Deal?," which she presented at the annual convention of the American Association of Equine Practitioners in December.

"We as equine practitioners can show we are doing our part to limit the development of antimicrobial resistance by working with our clients to help them keep their animals healthy in the first place," she says.

The paper is a joint collaboration of Traub-Dargatz, Dr. David Dargatz and Dr. Paul S. Morley, all professors at Colorado State University.

The presentation concerned the evolving issues regarding bacteria resistant to one or more antimicrobials that then may infect their equine patients or themselves.

A meatier issue

Although antimicrobial resistance most frequently dominates food animal circles, Traub-Dargatz says equine veterinary practitioners should be equally concerned for several reasons:

* The documented occurrence of resistant infections in equine patients.

* The likelihood that few, if any, new antimicrobials will reach the market for veterinary use.

* Potential public health impacts of resistant bacterial infections.

No scientific proof

The authors agree that most information needed to determine the extent of the antimicrobial resistance problem in equine medicine is lacking. Since there is no national system tracking antimicrobial resistance of animal pathogens, Traub-Dargatz says the frequency of treatment failure due to antimicrobial resistance in equine patients is unknown.

Compound that with the unlikely event that new antimicrobials will even reach the market in the future.

"The more drugs have an impact on human health, the harder it will be to get drugs approved in food animal, eventually, equine and small animal," says Traub-Dargatz. Not to mention the cost-prohibitive factor - the cost to bring a new drug to market today is at least $300 million, experts estimate.

Professional attempt

Whether new drugs are introduced or not, Traub-Dargatz says she commends the AAEP for taking the initiative for the equine profession when it introduced the "Prudent Use Guidelines for Antimicrobials" in 2001, jointly approved by the AAEP board and the executive board of the American Veterinary Medical Association. The guidelines outline appropriate use of antimicrobial drugs for equines. Find them online at www.avma.org/scientist/-jtua/equine/jtuaequine.asp.

"AAEP prudent use principles are a good starting place," adds Morley. "From a professional perspective, we can point to them and say we are concerned about this ­ this is our official statement.

"I think we need to go further. They don't specifically tell a veterinarian in practice how they should and shouldn't use antimicrobials. That's the next step," he says.

Building on the groundwork laid by AAEP, the American College of Veterinary Internal Medicine has asked Morley to chair an ad hoc committee to prepare a consensus statement regarding antimicrobial use among specialists of all species.

"I hope we will go another step in recommending how specialists should consider use of antimicrobial drugs and go beyond what is stated in the prudent use guidelines," says Morley. The statement will be prepared by the June meeting of the ACVIM.