A superbug called Salmonella has become a growing public health concern. It is antibiotic-resistant, meaning it has attracted attention due to its ability to escape treatment and spread through various transmission points.

While traditionally associated with contaminated food and direct contact with infected humans or animals, a recent study by Penn State researchers has highlighted domestic dogs as an important and neglected source of zoonotic Salmonella infection.

Published in Zoonoses & Public Health, the study highlights dogs’ close proximity to humans and their ability to transmit antimicrobial-resistant Salmonella. This zoonosis—disease spread from animals to humans—is particularly worrisome given the close relationships between dogs and their owners.

Erica Ganda, lead researcher and assistant professor at Penn State, said that while Salmonella infection in dogs can be symptomatic or asymptomatic, healthy dogs often carry the bacteria. Improper food handling and contamination in pet handling can increase the risk of transmission.

Ganda explained that bacteria are never completely “bad” or “good”, their role depends on the context.

While some bacteria, such as Salmonella, can pose serious health risks, others are essential to maintaining our health and the health of our pets.

It’s important to remain vigilant and informed about potential risks, she said, especially when living with animals.

The study analyzed 87 nontyphoidal Salmonella cases in domestic dogs from 2017 to 2023, leveraging biosurveillance data from the US FDA’s Veterinary Laboratory Detection and Response Network.

These cases were matched to human infections in the National Center for Biotechnology Information database, resulting in 77 suspected zoonotic cases in 17 US states.

The strains found in dogs included diverse serotypes medically relevant to human health. All identified strains contain antimicrobial resistance genes to drugs classified as critical or extremely important by the World Health Organization (WHO).

Doctoral student Sophia Kenny, who led the study, pointed to the unique role of dogs in disease transmission: “We don’t let cows sleep on our beds or lick our faces, but we do let dogs do that. This close relationship creates a high risk of zoonotic disease transmission.

Co-author Nakuchia Mikanatha recalled a previous outbreak of multidrug-resistant Salmonella linked to pig ear pet treats, which sickened more than 150 people in the US. He stressed the importance of basic hygiene practices like hand washing for the safety of both pets and humans.

Ganda stressed that the goal is not to discourage pet ownership but to raise awareness of the potential risks. Simple hygiene measures can ensure the safety of both families and their furry companions.