Prudent use key to key to keeping swine medications effective and accessible
The prudent use of antibiotics is key to treating and preventing bacterial diseases, maintaining efficient production and ensuring food safety, thus stressing the need to keep antibiotics accessible and effective through increased pharmacovigilance, an expert says.
“Antibiotics are a very important family of drugs, and they are part of a total herd-health management plan, along with biosecurity, vaccines and animal management,” said Lorenzo Fraile, DVM, of Spain’s University of Lleida, speaking at the European Symposium of Porcine Health Management 2020+1 meeting.
“While antibiotics are commonly used to treat sick animals with bacterial disease, they’re also necessary to treat at-risk populations. We need to keep them accessible and effective; that means prudent use,” he added, stressing that prudent use requires a vigilant commitment from the farmer and the swine veterinarian on a daily basis.
Know the details
It’s important to understand the legislation and hierarchy of agencies involved in registering and using animal medications in the EU, Fraile said.
First, under European legislation, any veterinary medicinal product (VMP) must be registered across Europe through the European Medicines Agency (EMA) or following national registration procedures. These registration procedures have been developed to assure that the VMP is safe and effective for the target species and also safe for the user (veterinarian or farmer), the environment and for the consumer.
“This all takes a significant amount of time to secure a registration,” Fraile noted. “It’s not uncommon for a company to spend 5 to 8 years to get a product to market.”
Once approved, an equally important part of maintaining the efficacy of and access to a swine medication is pharmacovigilance, or the reporting and investigation of any adverse events potentially associated with a VMP. Overall, the greatest number of adverse reports have come from the pet sector, with very few cited in pig production.
However, Fraile cautioned that may be due to under-reporting, and more diligence is required. He noted that the EMA plans to hold pharmacovigilance focus-group meetings with food-animal veterinarians to discuss the importance of such reporting and to gather more information on each VMP.
Prioritizing food safety
The end goal of everyone involved with food-animal production is to ensure a safe food supply, Faile said. Part of that includes monitoring withdrawal times and residue limits.
“The EU legislative framework clearly establishes the monitoring system for residues in food,” Fraile said. “We cannot expect a zero level — it’s a minimum.”
For swine, the minimum number of pigs tested for all kinds of residues and substances each year is 0.05% of the previous year’s slaughter numbers. He noted that over the past 10 years, the percentage of non-compliance in pigs has been consistently, extremely low, suggesting that “withdrawal periods are almost always respected, and non-compliant samples can be associated with non-deliberate mistakes.”
Different countries have different regulations regarding antimicrobials, and veterinarians need to review and follow them accordingly. In Europe, the EMA has classified antibiotics into four categories by their risk of developing resistance, from a Global One-Health point of view.
“Read this carefully,” Fraile said. “We must use these medications from the bottom up.”
- Category A (Avoid): Includes antimicrobial classes not currently authorized in veterinary medicine in the EU. These medicines are banned for use in food-producing animals and may be given to individual companion animals only under exceptional circumstances.
- Category B (Restrict): Refers to quinolones, third- and fourth-generation cephalosporins and polymyxins. Use in animals should be restricted to mitigate the risk to public health.
- Category C (Caution): These antimicrobials should be used only when there are no antimicrobial substances in Category D that would be effective.
- Category D (Prudence): This is the lowest risk category, and these antimicrobials can be used in animals in a prudent manner. This means unnecessary use and long treatment periods should be avoided, and group treatment should be restricted to cases where individual treatment is not feasible.
“It seems that today there is pressure to avoid the use of antimicrobials under any circumstances,” Fraile said. “This point is a conceptual error. The use of antimicrobials to cure sick animals due to bacterial diseases is mandatory and unquestionable.”
Prudent use is the priority, and there is no shortage of recommendations from official sources, Fraile noted. He offered this decision tree as a guide.
Reconciling clinical urgency with prudent use
The challenge for veterinarians is how to carry out prudent use in daily practice because the underlying cause of the health issue is not always clear. Also, the microbiological diagnosis and determining the antimicrobial sensitivity can take 4 to 6 days to achieve.
Reconciling the prudent use of antimicrobials with the clinical urgency to treat animals may be achieved, Fraile said, if the epidemiological information is applied more broadly. For example, “the microbiological diagnosis and the determined antimicrobial sensitivity can be used for all clinical cases caused by the identified bacterium within the same production system if an epidemiological link is established.” The swine sector in Spain is testing this approach.
In the end, Fraile said, that to achieve prudent use of antimicrobials “we will need the cooperation of farmers to apply the treatments correctly, and we need to work together to share information.”
Posted on June 23, 2021