Study proposes US reporting framework for pet carbapenem resistance

A new AJVR study is tackling a problem many veterinary and public health teams have been improvising around: what should happen after a carbapenem-resistant organism is detected in a dog or cat. The paper, “A framework for reporting carbapenem-resistant organisms in companion animals in the United States,” examines current reporting and communication practices and evaluates an interagency communication algorithm using survey data collected through the National Association of State Public Health Veterinarians from November 2024 through March 2025. (pubmed.ncbi.nlm.nih.gov)

The timing makes sense. Carbapenem-resistant organisms in companion animals are still uncommon, but concern has been building for years as veterinary hospitals, diagnostic labs, and public health agencies have confronted sporadic detections, outbreaks, and uncertainty over who should be notified. A 2020 US survey of veterinary diagnostic laboratories found that nearly all responding labs tested for carbapenem resistance, but only about one-third had carbapenemase testing capacity, 35% said they would notify public health after a detection, and most were not aware of reporting mandates. That left a clear gap between detection and coordinated response. (pubmed.ncbi.nlm.nih.gov)

More recent research has sharpened the stakes. A CDC-led 2026 analysis of publicly available US companion-animal carbapenemase-producing CRE sequences found that 169 of 246 animal isolates, or 69%, fell into One Health clusters with human isolates. The clustered isolates were collected from 2016 through early 2024, were dominated by New Delhi metallo-β-lactamase genes, and included closely related human and animal strains, suggesting shared reservoirs or transmission pathways. The authors stopped short of claiming direct transmission in every case, but concluded that exchange between humans and companion animals is occurring in the United States. (wwwnc.cdc.gov)

That helps explain why reporting frameworks matter. CDC describes carbapenem-resistant Enterobacterales as resistant to one or more carbapenems, with carbapenemase-producing strains posing a particularly important public health risk. The agency also notes that standard infection-prevention measures in veterinary facilities are important because colonized animals may spread these organisms, and antibiotics do not decolonize them. In practice, that means a reporting algorithm is not just a paperwork exercise; it can shape isolation decisions, environmental cleaning, staff precautions, referral communication, and conversations with pet parents. (cdc.gov)

There are already models pointing in that direction. New York City amended its Health Code to require reporting of carbapenem-resistant organisms detected in animals to the health department, and the city has said the goal is to help contain spread, support infection-control measures, and improve understanding of animal CRO epidemiology. Separately, University of Pennsylvania guidance for veterinary microbiology labs recommends clearly labeling carbapenem-resistant Enterobacterales in reports and documenting whether the organism has been reported to public health officials. A 2023 One Health reporting project in Kansas and Missouri similarly described building a prototype protocol to surveil, store, and report veterinary CRE isolates to state and national public health partners. (rules.cityofnewyork.us)

Expert and industry commentary around this issue has been moving in the same direction. A 2025 Frontiers paper describing state-level work linking companion-animal and human carbapenemase-producing Enterobacterales through whole-genome sequencing called it one of the first operational One Health models of its kind and argued for stronger communication between veterinary and public health sectors. Cornell also launched a 2025-2026 UnCOVER-Cats project focused on resistance to last-resort drugs in companion animals, underscoring that academic and public health interest is shifting from isolated case reports toward systems for surveillance and response. (pubmed.ncbi.nlm.nih.gov)

Why it matters: For veterinary professionals, the value of a reporting framework is consistency. When a CRO result lands, clinicians and diagnostic labs need to know whether to notify local or state public health officials, what information to share, how to communicate risk without overstating it, and what infection-prevention steps should be triggered inside the clinic or hospital. That’s especially important because many animal detections may involve colonization rather than active infection, yet still carry implications for hospital spread, staff exposure, and household counseling. A more standardized pathway could also reduce the uncertainty that has historically left labs and clinicians guessing about their responsibilities. (wwwnc.cdc.gov)

What to watch: The next question is whether this framework stays academic or starts shaping policy and practice. Veterinary professionals should watch for publication details from AJVR, uptake by state public health veterinarians and diagnostic labs, and whether more jurisdictions follow New York City’s lead with explicit animal CRO reporting requirements or formal interagency communication protocols. (nyc.gov)