A pug rests under a comforter in bed, his pink tongue poking out slightly, as though he is sick.

Of the 118 people who became sick during a recent outbreak of a serious stomach bug, at least 101 of them had something in common: recent contact with a puppy from a pet store.

Although this wasn't the first time dogs had been found to spread a bug to people, this was the first such outbreak of campylobacter (a common diarrheal illness) where the bacteria was resistant to antibiotics—which often makes it harder to treat.

The problem of antibiotic resistance is well-known in humans.

According to the Centers for Disease Control and Prevention, about 1 in 3 antibiotic prescriptions isn't actually necessary. Taking an antibiotic you don’t need can lead to dangerous side effects, and also contributes to the development of antibiotic-resistant bacteria that can cause serious illnesses and make antibiotics less effective.

more on antibiotics

But health experts say that this problem isn’t limited to humans and farm animals raised for food. In many cases, companion animals like cats and dogs also receive antibiotics they don’t need. And antibiotic-resistant bacteria can develop in pets, just as they can in humans.

The CDC says that’s probably what happened in the recent case of the puppies.

Researchers reviewed records on 149 pups and found that at some point on their journey to pet stores, 95 percent of them had received one or more courses of antibiotics. More than half of those puppies weren’t sick when they received the meds. Handling the animals or cleaning up after them is probably what caused pet store employees and new owners to get sick—campylobacter can be transmitted via contact with infected feces.

Although the overuse of antibiotics is a major health concern, the situation in humans is slowly improving, according to the CDC. “We really do have a more educated populace that is concerned about overuse or side effects from antibiotics,” says Jeff Bender, D.V.M., a professor in the School of Public Health and the College of Veterinary Medicine at the University of Minnesota.

But there’s been a piece missing in the dialog, according to Bender. “What’s been neglected has been this discussion about companion animals,” he says.

Although events like the campylobacter outbreak originating in puppies are rare, it’s certainly possible for humans to contract dangerous, drug-resistant bacterial infections from their pets. And even if they don’t pass them to their owners, these infections can cause significant suffering to pets themselves.

Here’s what you need to know about the use—and overuse—of antibiotics in pets, and what you can do to protect both yourself and your furry friends.

Overuse of Antibiotics in Pets

In the recent campylobacter outbreak, it may have been that the puppies’ caretakers were attempting to reduce the likelihood of the puppies picking up bacterial infections from one another. A single pup may come into contact with many others in the process of being transported to a pet store, says Megin Nichols, D.V.M., M.P.H., a public health veterinarian with the CDC.

When you’re first bringing home a puppy or a kitten (or a dog or cat), you probably don’t have much control over what medications they received before you met them. But misuse of antibiotics doesn't just happen in pet stores. It can also occur at your vet’s office.

The data about the overuse of antibiotics in veterinary offices and hospitals isn’t as robust as it is for humans, in whom the problem has been studied for decades. But the experts we consulted said that just like in human clinics, pets often receive antibiotics they don’t need.

One 2011 study, published in the Journal of Small Animal Practice, evaluated a random sample of antibiotics prescriptions in dogs over the course of a year at one veterinary hospital. The scientists found that about 38 percent of all antibiotics prescriptions were given to dogs that showed no evidence of needing an antibiotic—some even had test results that were negative for a bacterial infection.

Once drug-resistant bacteria develop in pets, they can cause dangerous outbreaks.

A 2016 study in the Journal of Small Animal Practice found that one outbreak of antibiotic-resistant bacteria in an Israeli animal hospital killed 16 out of 23 infected dogs and cats. According to a 2017 analysis in the journal Veterinary Microbiology, drug-resistant strains of MRSA, E. coli, salmonella, and others have all been found in pets.

Veterinarians, like Jennifer Granick, D.V.M., Ph.D., assistant professor of small animal internal medicine at the University of Minnesota, say that they have seen these infections in their patients.

“We know that antibiotic resistance is an issue in small animals, because we see it clinically,” she says.

How to Keep You and Your Pet Safe

Overall, the risk picking up any type of bug from your pet, whether an antibiotic-resistant bacteria or some other kind of infection, is low. Many illnesses that infect animals can't be transmitted to humans.

But it’s still a real possibility. And anyone whose immune system isn’t fully functional—including older adults, young children, pregnant women, and people who have chronic health conditions—is at an increased risk of picking up an infection from an animal.

You can take a number of simple steps to keep yourself and your pets healthy, both when you visit your vet and at home.

If your pet is sick, don’t rush to antibiotics. The principles of smart use of antibiotics in humans all apply to animals as well, experts say. That means that if your dog or cat is sick, let your vet know when you visit that you don’t want antibiotics for your pet unless they really need it. If the vet recommends an antibiotic, Granick says, ask: Do we really need this? Find out whether there are non-antibiotic options the vet can try first.

Your vet may recommend taking a wait-and-see approach with your pet—allowing time to see whether the illness goes away on its own, as many viral infections do. A guideline for treating upper respiratory tract infections in cats and dogs, published by the International Society for Companion Animal Infectious Diseases, for example, recommends that for cats, even if a vet suspects the infection might be due to a bacteria, it’s best to wait up to 10 days to see whether the infection resolves itself before using an antibiotic.

And ask about the possibility of diagnostic tests that might help identify the cause of your pet’s illness. Vets may be hesitant to offer these, Granick notes, because many owners don’t have pet insurance and might be wary of the costs. But if you can afford them, tests can help pinpoint which type of antibiotics would be best if your pet’s infection is bacterial. And getting the treatment right the first time could reduce your costs in the long run, Granick says.

Preventive care is best. The best way to reduce the risks of antibiotics is to keep your furry friends from getting sick in the first place, says Scott Weese, D.V.M., D.V.Sc., a professor of infectious disease at Ontario Veterinary College at the University of Guelph, who has developed guidelines for antibiotic use in pets.

Vaccinations are key, so keep your pets up to date on their shots. And work with your vet to address other health problems your animals may have. Bacterial skin infections in dogs, for example, are usually a secondary result of some other problem, often an allergy, according to Weese. If you can effectively treat the underlying allergy, he says, then you reduce the risk of your dog getting a skin infection later.

Practice good hygiene at home. Diligent handwashing is key to preventing infections—in pets as well as people. It may seem extreme, but the CDC recommends washing hands after touching animals. Take special care to wash after cleaning up after them—especially picking up feces or scooping out a litter box. Be sure to coach children about the importance of handwashing, especially after bringing home a new pet. Launder pets’ bedding weekly.

And try to limit the most risky kinds of contact, recommends Bender—you may want to consider not letting your dog lick your face, for instance. Try to avoid bites from any pet, and note that cat bites are more likely to cause infection than dog bites, Bender says.

Feed pets a safe diet. Raw pet food can be contaminated with bacteria such as salmonella, which can sicken pets as well as humans who handle the food. Also, “pets that eat raw food are at increased risk of shedding antibiotic-resistant bacteria,” Weese notes. The Centers for Disease Control recommends against raw diets for pets.