Your pet could be making you sick: Antibiotic-resistant bacteria spreading from dogs and cats to humans

LISBON, Portugal — Could the next global pandemic come from our pet dogs and cats? Researchers from the University of Lisbon warn that our furry companions may inadvertently be harboring and spreading dangerous antibiotic-resistant bacteria onto humans.

Antibiotic resistance is a growing global health threat. When bacteria become resistant to the drugs designed to kill them, even common infections can become deadly. According to the World Health Organization, drug-resistant infections already claim over 1.2 million lives each year worldwide. If no action is taken, that figure could skyrocket to 10 million annual deaths by 2050.

The researchers tested samples from cats and dogs with skin and urinary tract infections, as well as from their healthy human owners, in households in Portugal and the United Kingdom. They were looking for a family of bacteria called Enterobacterales that had become resistant to common antibiotics.

In particular, they focused on resistance to two critical antibiotic classes: third generation cephalosporins and carbapenems. Cephalosporins are used to treat serious infections like pneumonia, meningitis, and sepsis. Carbapenems are often the last line of defense when other antibiotics fail. Losing these drugs to resistance would be devastating for public health.

The results were concerning. In Portugal, over half of the pets and a third of the owners carried bacteria resistant to cephalosporins. Even more worryingly, one dog harbored a strain resistant to carbapenems. In the UK, over a third of the dogs and an eighth of the owners had cephalosporin-resistant bacteria, with one dog carrying a strain resistant to multiple drug classes including carbapenems.

But the smoking gun came from genetic analysis. In several households, the resistant bacteria in the pet and the owner were revealed to be the same strain — strong evidence of transmission between them. In a few cases, the timing of the positive tests suggested the direction of transmission was from pet to human.

“Our findings underline the importance of including pet-owning households in national programs that monitor levels of antibiotic resistance,” says lead researcher Juliana Menezes, of the University of Lisbon’s Antibiotic Resistance Lab at the Center of Interdisciplinary Research in Animal Health, in a media release.

Scientists have been studying for decades about viruses jumping from animals to people. The deadly COVID-19 pandemic that caused worldwide lockdowns is believed to have originated from a wet market in Wuhan, China, in late 2019. According to a 2022 study published in the journal Science, researchers believe the virus that killed millions globally passed from a caged wild animal into humans at the Huanan Seafood Wholesale Market.

Recently, a person in Texas contracted bird flu, making it the second human case H5N1 bird flu reported in the United States, according to the Centers for Disease Control and Prevention. More than 460 people have died worldwide from the bird flu in the last two decades.

“Recent research indicates that the transmission of antimicrobial resistance (AMR) bacteria between humans and animals, including pets, is crucial in maintaining resistance levels, challenging the traditional belief that humans are the main carriers of AMR bacteria in the community,” Menezes says. “Understanding and addressing the transmission of AMR bacteria from pets to humans is essential for effectively combating antimicrobial resistance in both human and animal populations.”

woman lying beside two kittens
(credit: Photo by Tran Mau Tri Tam ✪ on Unsplash)

So how can resistant bacteria spread from Fido or Fluffy to you? Close contact is key. Petting, touching, kissing, and handling pet waste can all potentially transfer bacteria. But don’t panic and get rid of your beloved companion — practicing good hygiene can go a long way to reducing the risk.

“When your pet is unwell, consider isolating them in one room to prevent the spread of bacteria throughout the house and clean the other rooms thoroughly,” adds Menezes.

It’s important to note that in this study, none of the owners developed infections themselves, and all the pets were successfully treated. But the presence of resistant bacteria, even without causing immediate illness, still contributes to the overall problem of antibiotic resistance.

Woman with her dog
(Photo by Tamas Pap on Unsplash)

Researchers believe this study highlights a need for pet-owning households to be included in national antibiotic resistance monitoring.

“Learning more about the resistance in pets would aid in the development of informed and targeted interventions to safeguard both animal and human health,” concludes Menezes.

Our pets are cherished family members. Protecting their health helps protect ours too. With a combination of good research, smart policies, and responsible pet ownership practices, we can ensure that the special bond between humans and animals remains a source of companionship and comfort, not a conduit for dangerous superbugs. The fight against antibiotic resistance will take efforts on all fronts — and that includes our furry friends.

The findings will be presented at the European Society of Clinical Microbiology and Infectious Diseases Global Congress from April 27-30 in Barcelona, Spain.

StudyFinds’ Matt Higgins contributed to this report.

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  1. You guys are so full of it. You told the truth for about 2 days then you have constantly reported bs ever since

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