The study by the University of Lisbon found that several pets in Portugal and one in the UK were found to be carrying similar antibiotic-resistant bacteria to their owners.
Scientists say that the bacteria could include E. coli and another type linked with pneumonia.
Juliana Menezes, a University of Lisbon PhD student, said: “In this study, we provide evidence that bacteria resistant to a third generation cephalosporins, critically important antibiotics, are being passed from pets to their owners.”
“Dogs and cats may aid the spread and persistence of such bacteria in the community and it is vitally important that they are included in assessments of antimicrobial resistance.”
“Owners can reduce the spread of multidrug-resistant bacteria by practicing good hygiene, including washing their hands after collecting their dog or cat’s waste and even after petting them.”
A total of five cats, 38 dogs, and 78 humans from 43 households in Portugal were studied, as well as seven dogs and eight humans from seven UK households.
Out of the whole group, three cats, 21 dogs, and 28 owners tested positive for bacteria resistant to key third generation cephalosporins.
The study did not determine whether the bacteria was transferred from pet to human or vice versa.
Researchers ensured that all of the pets were treated for their conditions. Owners were not sick and did not receive treatment.
Drug-resistant infections kill roughly 700,000 people per year around the world. It is estimated that this figure will rise to 10 million by 2050 if no action is taken.
The World Health Organization (WHO) has dubbed the phenomenon one of the greatest public health threats facing humanity.