Zoetis report shows low antimicrobial resistance in swine respiratory pathogens, but tetracycline resistance persists

Zoetis’s latest surveillance indicates antimicrobial resistance remains uncommon in most swine respiratory pathogens, highlighting the impact of diagnostic-led prescribing. However, persistent tetracycline resistance underscores the need for continued vigilance in antimicrobial stewardship within the industry.

Zoetis’s latest surveillance of swine respiratory pathogens suggests antimicrobial resistance remains uncommon across most of the drugs tested, a reassuring signal for pig producers and veterinarians trying to preserve treatment options. The pattern matters beyond animal health: it points to a sector in which stewardship and diagnostic-led prescribing may still be containing one of the industry’s most costly biological risks. Even so, the persistence of higher tetracycline resistance shows how quickly hard-won gains can narrow.

According to Zoetis, the 2025 dataset is based on isolates collected from more than 25 diagnostic laboratories in the United States and Canada, with roughly 800 to 1,000 samples processed each year. The company says the programme has run for more than 28 years and uses minimum inhibitory concentration testing under Clinical and Laboratory Standards Institute methods.

The headline finding is encouraging. Zoetis says Actinobacillus pleuropneumoniae and Pasteurella multocida were fully susceptible to several key antibiotics, while Streptococcus suis and Bordetella bronchiseptica also showed low resistance. Tetracycline was the main exception.

The results echo recent European research, which found similarly low resistance in bovine and porcine respiratory pathogens, apart from tetracycline. For an industry under pressure to reduce antibiotic use without losing therapeutic effectiveness, that convergence is significant: it suggests surveillance, not habit, is increasingly shaping treatment decisions.