You Might Be Surprised To Learn What’s On Your Dog’s Paws

When you take your dog on a walk, you may wonder what kind of germs are sticking to their paws as they trot along a city sidewalk, open field or hiking trail.

In the city where I live, for example, I often wince when I see my dog do his business on tiny patches of dirt and grass knowing that thousands of other dogs recently used the same area as a bathroom. There’s no denying he’s walking on other dogs’ urine and feces, maybe some squirrel and goose droppings, but could he be bringing germs into our home that could make us sick?

According to Dr. Jane Sykes, a professor of small animal internal medicine and a board-certified small animal internal medicine specialist at the UC Davis School of Veterinary Medicine, dogs — their coats, mouths, paws — are covered in bacteria, but that doesn’t necessarily spell danger. Here’s what to know:

It’d take a very resilient bug — and a lot of it — to cause human illness. It’s not unheard of, but in general, the health benefits of adventuring with your pup far outweigh the tiny risks of getting sick from whatever may be latching to your dog’s paws.

“If you just go out for a walk in an urban area and you are not seeing any gross contamination with fecal matter, then it’s probably okay to do nothing, because you’ve got it all over your shoes the same way a dog has it on its paws,” Sykes said.

The type of germs your dog’s paws pick up depends on where you live, what your lifestyle’s like, and the type of pathogens that exist in your area. For example, dogs in cities are going to be exposed to germs that are different from what dogs are in rural areas or farmland walk on, which won’t look like the pathogens that attach to your dog’s fur when they swim in lakes and ponds.

Most viruses your dog walks and rolls around in don’t survive well in outdoor environments and likely wouldn’t be viable by the time they reach the indoors, Sykes explained. “They’re just not infectious anymore,” she said.

As mentioned above, dogs are already coated in bacteria that they bring into the home, but the bulk of these germs aren’t pathogenic, meaning they don’t cause illness in people and animals, added Megan Jacob, a professor of veterinary microbiology at North Carolina State University.

Furthermore, your dog’s paws probably wouldn’t pick up enough of a pathogen, aka a high enough infectious dose, that’d cause disease, Sykes said. Plus, as your dog continues walking, a lot of organisms will fall off of their paws before you get back to your house.

Say, for example, your dog walked through a mound of feces deposited by another animal. According to Jacobs, that bacteria probably wouldn’t be stuck to their paws for very long. “Every step that he took after that pile, he’d probably be losing some of the bacteria he encountered,” Jacob said.

That said, it’s entirely plausible your dog could track something into the home that has the potential to make you ill. Any time your dog comes into contact with another animal’s feces, there’s at least a little bit of a risk that organisms could be crawling around.

This is mostly a problem on farmland or in rural areas with cows or birds as they carry bacteria, like salmonella, and parasites that can be pathogenic to humans, Jacob said. Dogs can also pick up bacteria, like pseudomonas or aeromonas, from swimming in lakes and ponds, which can cause infections in people.

The fungal threats, which reside in soil and dirt in certain parts of the country, to be aware of are histoplasmosis, blastomyces, coccidioidomycosis, and cryptococcosis. “There is the potential, if dogs are bringing a lot of dirt into the home, for them to bring some of those organisms in,” Sykes said. When inhaled, they can lead to infections, though most people won’t get too sick, if at all.

It’s uncommon to contract a parasitic infection from your dog (again: It can and has happened). These critters are often more active in warm, humid environments. The main one is Giardia, which is spread through traces of contaminated feces in the environment. If your dog brought Giardia home, you could, in theory, come in contact with it and get infected if you didn’t wash your hands before eating, Sykes said.

There are the usual offenders, too: fleas, ticks, and worms (though your vet likely has your dog on a good preventative for these). “There are several reports of dogs bringing ticks and fleas into the home and then those ticks and fleas feed on people and they have pathogens in them that cause human disease,” Sykes said.

As for your dog walking on other dog’s poop, aside from trying to avoid that altogether, steer clear of other dog’s diarrhea. This suggests that whatever dog excreted it may be sick. According to Jacob, more dogs are eating raw meat diets and run the risk of contracting and spreading salmonella and listeria. They could shed those germs when they go out and do their business, passing it on to other dogs — and, potentially, you. (But, even then, the dog would probably walk off that bacteria, Jacob said.)

You don’t need to suddenly keep your dog squeaky clean. It’s actually good for us to be around all kinds of germs from the environment. “The more we get exposed, we sort of prime our immune system” to respond to bacteria that are pathogenic, Jacob said.

Not to mention, the benefits of the human-dog relationship far outweigh any risks of being exposed to a harmful germ on your pet’s paws or coat, Sykes said. Our furry friends make us happier, reduce our stress levels, help us get more exercise and keep us healthier.

When venturing out with your pup, take a look at your environment because the risk will vary depending on where you’re headed. Going on a walk through your neighborhood, for example, is a pretty low-risk activity. But if your dog went running through a cow pasture or wading in a creek, it may be worth scanning them for ticks, giving them a bath or wiping off their paws to get rid of any pathogens, Jacob said. Washing your hands before eating can lower your risk of getting sick, too.

All in all, the odds your dog is going to trot over some organism that’s going to make you sick is pretty low. So, go on the hike, explore the city, take your dog to the farm — just keep an eye on them, and if the area felt risky, give them a quick clean. It can’t hurt.