Acting Now to Preserve Our Future

The 2022 AAFP/AAHA Antimicrobial Stewardship Guidelines help veterinary teams safeguard vital antimicrobial drugs

by Tony McReynolds

Antimicrobial resistance—the ability of pathogens like bacteria and fungi to evade antimicrobial drugs—is an issue of growing urgency worldwide, and the veterinary profession is not immune to this threat. Antimicrobial-resistant infections endanger both humans and animals and present what may be one of the direst public health crises of the past few decades. In 2019, the World Health Organization listed antimicrobial resistance as one of the 10 most urgent global threats. A 2022 global study published in The Lancet estimated that antimicrobial resistance contributed to nearly 1.3 million human deaths in 2019 and played a role in an additional five million deaths. Cases of antimicrobial-resistant infections are rising in animals as well.

Antimicrobial resistance is a complex problem caused by a variety of factors, but how and when we use and dispense antibiotics in our veterinary practices plays an important role. If antimicrobial resistance is permitted to continue to develop unchecked, veterinary teams will be faced with the very real possibility that in the near future, antimicrobial drugs needed to treat infections may not be available.

What is Antimicrobial Stewardship?

The 2022 AAFP/AAHA Antimicrobial Stewardship Guidelines provide veterinary team members with guidance on preserving the effectiveness of antimicrobial drugs, by implementing simple steps to practice antimicrobial stewardship. This concept was first defined for the veterinary profession by the American Veterinary Medical Association (AVMA) Committee on Antimicrobials in their 2020 report “Antimicrobial Resistant Pathogens Affecting Animal Health in the United States.” It defines antimicrobial stewardship as “the actions veterinarians take . . . to preserve the effectiveness and availability of antimicrobial drugs through conscientious oversight and responsible decisionmaking while safeguarding animal, public, and environmental health.”

Erin Frey, DVM, MPH, DACVPM, served as the 2022 guidelines Task Force Chair and represents AAHA as a member of the AVMA Committee on Antimicrobials. In that capacity, she helped craft the definition of antimicrobial stewardship in 2020 and ensured that AAHA’s antimicrobial stewardship efforts complemented the AVMA’s, as well as the efforts of other stakeholders invested in promoting antimicrobial stewardship. Frey noted that the AVMA report was the result of the combined efforts of veterinary organizations, species groups, and federal agencies responsible for oversight of food safety and public health.

The AVMA report articulated several core principles of antimicrobial stewardship that can be adapted to clinical practice. According to Frey, an important priority of the 2022 guidelines was to make sure that every member of the hospital team understands the importance of antimicrobial stewardship and can apply these core principles to their work, regardless of position.

The core principles of antimicrobial stewardship as defined by the AVMA and endorsed by AAHA and the AAFP are:

• Commit to stewardship
• Advocate for a system of care to prevent common diseases
• Select and use antimicrobial drugs judiciously
• Evaluate antimicrobial drug use practices
• Educate and build expertise

What’s New in the Guidelines?

The 2022 Guidelines offer guidance specifically tailored to companion animal veterinary practices and remain in sync with the broader landscape of antimicrobial stewardship. The 2022 Guidelines, which update the 2014 AAFP/AAHA Basic Guidelines for Judicious Therapeutic Use of Antimicrobials, have integrated a more holistic approach to preserving antimicrobials that doesn’t just focus on when and how to prescribe. According to Frey, “that was really the focus back then: What does a veterinarian do at the time of prescribing? How can you thoughtfully consider when to use antibiotics? What to use? And when to stop?”  

She said that focus changed in 2016 when the AVMA Committee on Antimicrobial Stewardship was first tasked to come up with a definition of antimicrobial stewardship. That involved taking a look at antimicrobial use on a more global level—with an emphasis on preventive medicine. The 2022 Guidelines reflect this broader approach.

“Every time you take an antibiotic, you’re changing the flora, opening up the possibility of resistance to infection.” Frey said a big part of stewardship involves being more deliberate in your choice of treatment and using discernment to identify situations where antibiotics aren’t necessary.

She noted that in the past, veterinarians would automatically prescribe antibiotics to treat certain routine conditions, from dental infections to diarrhea. “That time has passed,” said Frey. “That’s not appropriate anymore.” The guidelines promote thinking about ways we can limit automatic responses like that “and get veterinarians thinking about what they’re seeing in front of them.”

For example, “If a lab culture shows bacteria in the bladder but the patient doesn’t have clinical signs of infection, if they’re asymptomatic, then they don’t necessarily have a urinary tract infection and may not need an antimicrobial.”

Implementing Antimicrobial Stewardship

J. Scott Weese, DVM, DVSc, DACVIM, associate professor in the Department of Pathobiology at the University of Guelph (UG) in Ontario, Canada, also served on the task force for the 2022 AAFP/AAHA Antimicrobial Stewardship Guidelines. For the veterinary industry, antimicrobial resistance is an urgent issue because it’s impacting our patients, said Weese. “We’re seeing more resistant infections, and those can result in poor outcomes, longer treatments, more cost, more adverse effects, and other challenges.”

Weese said the 2022 Guidelines dovetail with other efforts in the veterinary space to encourage antimicrobial stewardship by providing the clinical details that companion animal practitioners need: “Broad statements about using antibiotics right, not overusing them, and similar content are fine, but they don’t tell you how to treat that patient in front of you,” noted Weese. “[The new] Guidelines help us manage patients, and that’s the biggest way to improve use.” He conceded that they’re not perfect: “We have limited evidence for many areas, but they’re a start.”

Tools for Antimicrobial Stewardship

According to the Guidelines, antimicrobial stewardship includes:

• Having a valid veterinarian-client-patient relationship in all cases where antibiotics are prescribed
• Emphasizing preventive care and routine health monitoring to prevent possible infections before they occur
• Never administering prophylactic antibiotics in place of good health management
• Recognizing risk factors for infection
• Considering other therapeutic alternatives, e.g., topical treatments
• Using diagnostic testing to determine if infection is present and select appropriate antibiotics
• Basing duration of therapy on scientific and clinical evidence

Other strategies described in the Guidelines, like watchful waiting and antimicrobial time-outs, offer the veterinary team opportunities to be both flexible and vigilant about their patients’ care.

Frey said that the Guidelines serve as both an introduction to the concept and importance of antimicrobial stewardship, and as a directory of places where AAHA members can go to find out more: “In the guidelines, we lay out some high-level principles people can use, but also direct them to other resources that are very specific.”

The push for awareness is hugely important because while antimicrobial resistance isn’t new—“It’s been around since before we had antibiotics,” noted Weese—the concept of antimicrobial stewardship is.

Weese said antimicrobial resistance is a natural phenomenon: “Bacteria and fungi have been practicing biological warfare for millennia. . . . Since [they] were producing substances to kill each other, they developed ways to avoid that,” Weese said. “That’s how we got the idea—and most of the antibiotics” we use today.

Normally, the process of developing resistance would take place more slowly, but it’s been sped up and amplified within bacterial populations due to the widespread use of antimicrobials in both human and animal populations. “What we’ve done is greatly enhance that natural process by providing a lot more exposure.”

“[Stewardship is] not really on the radar for most people,” said Weese, but it’s something veterinarians do every day without knowing it. “Every time we make a decision to treat or how to treat, we’re applying stewardship tools.”

More to the point: Weese said that everything we do to optimize health and reduce disease minimizes the need for antimicrobials. “So, we’re just trying to get people to realize that and refine it so that the daily decisions both improve patient care and reduce resistance issues from developing.”

We Can’t “Kick the Can Down the Road Anymore”

	Read the Guidelines Online
The 2022 AAFP/AAHA Antimicrobial Stewardship Guidelines are available online at aaha.org/guidelines. The guidelines were supported by a generous grant from IDEXX Laboratories, Inc., and Zoetis.

Practitioners need to know about and begin prioritizing antimicrobial stewardship. “We need to improve antimicrobial use to improve patient outcomes, reduce resistance, and protect our future patients and the public,” said Weese.

Frey added, “The ultimate goal of antimicrobial stewardship is to preserve the effectiveness and availability of antimicrobials.” She noted that every time science discovers a new antimicrobial, all the way back to penicillin, it’s only a matter of time before they discover a pathogen that’s evolved to resist it.

“The thing that has gotten harder over time,’’ said Frey, “is that when antibiotics were first discovered, new ones came up fairly frequently, so if one didn’t work, we’d find another one that did. And if we found another one that didn’t work, we’d find yet another one that did.”

The problem is that now, science is discovering fewer new alternatives and there aren’t a lot more on the horizon. “In the past if a drug didn’t work, you could say, ‘well, drug companies will find something else, and I can just switch to that new thing.’ But where we are right now, even in companion animal medicine, we’re using generic antibiotics that have been around for decades. And there aren’t too many new ones coming out.”

She said the situation today is more serious than it was 20 years ago, or even eight years ago when the previous Guidelines came out. Hence the increased urgency about promoting antimicrobial stewardship.

“We have to make sure what we have right now continues to work. We can’t kick the can down the road anymore and say we’ll just use the next best thing. What we’ve got is what we’ve got, and we need to try and preserve it for as long as we can for the sake of our patients. Because pretty soon there isn’t going to be a next best thing.” 

Tony McReynolds is AAHA’s NEWstat editor.

Photo credits: SeventyFour/iStock via Getty Images; myshkovsky/iStock via Getty Images; SelectStock/iStock via Getty Images; Ridofranz/iStock via Getty Images