When a dog gets diagnosed with something, the questions come in a predictable order: Will they be okay? Can my other dog catch it? Can I? For the last one, the answer is reassuring more often than people expect. The large majority of infections a dog picks up are species-specific, meaning the germ is fussy about which host it can live in, and your body isn’t on the guest list. Your dog’s cold, your dog’s flu, your dog’s heartworm, none of those are coming for you.
But “mostly safe” isn’t “always safe,” and the useful version of this article isn’t a long scary list. It’s a short one, sorted by how much it should actually occupy your attention, plus the punchline that ties it together: nearly every real risk here is blunted by the least glamorous habit in the house, washing your hands. The technical word for a disease that can pass from animals to people is zoonotic, and here’s what’s worth knowing and what you can let go of.
The ones actually worth your attention
Intestinal parasites. This is the big one in everyday life. Roundworms, hookworms, and giardia spread by the fecal-oral route, which is exactly as unpleasant as it sounds: microscopic amounts of infected stool reach a mouth. You can pick these up after scooping the yard, after a nail trim if the paws walked through contaminated ground, or after gardening. Hookworms and roundworms can also go straight through skin, the classic case being bare feet on infested soil. The defense is boring and effective: keep your dog on monthly parasite preventatives, wear shoes where dogs relieve themselves, and wash your hands after cleaning up waste or grooming.
Intestinal bacteria. Salmonella, Listeria, and Campylobacter travel the same fecal-oral path. Salmonella is usually thought of as a food-borne illness and is uncommon in dogs, but the odds rise in dogs fed a raw diet. Same defense: hand hygiene, and a real conversation with your vet about the risks that come with raw food.
Skin conditions. Ringworm is a fungus, not a worm, and causes patchy hair loss and flaky skin, especially in puppies; sarcoptic mange (scabies) is a burrowing mite that causes intense itching and hair loss. People can catch both through direct contact with the lesions. Dogs also get bacterial skin infections, and antibiotic-resistant bugs like MRSA can move in both directions, though human-to-dog is the more likely path, and dogs can quietly carry these bacteria without symptoms. Get skin lesions or wounds checked promptly, wash your hands after handling a recovering dog, and keep any open wounds of your own covered around your pet.
Leptospirosis. A bacterial infection that targets the kidneys and can affect both dogs and people, usually through water contaminated with an infected animal’s urine. People can be infected by handling an infected dog’s blood or urine. Wash your hands after handling your dog’s bodily fluids even when it’s healthy, keep your dog from drinking or wading in standing water, and ask your vet whether the lepto vaccine makes sense where you live.
Rabies. Rare in vaccinated pets, but it belongs on any serious list because it’s nearly always fatal in both dogs and people. It’s typically transmitted through the bite of an infected animal. The entire management strategy is prevention: keep your dog vaccinated, which is also the law in most places.
“The honest framing isn’t ‘dogs are walking petri dishes,’ because they aren’t,” says Dr. Ravi Mehta. “It’s that a few specific infections cross over, and almost all of them are stopped by preventatives and clean hands. Do those two things and you’ve handled the bulk of the real risk.”
The ones you can genuinely cross off
Half the value of this list is deleting worries, so here’s what does not jump from your dog to you.
Heartworm. Spread by mosquitoes, and the transmission is species-specific to dogs. A mosquito can carry it between dogs, but you are not susceptible. (Your dog still needs monthly prevention, this is dangerous for them.)
Colds and flu. This one confuses people because the names overlap. An outbreak of “canine influenza” sounds like a threat to the household, but most flu viruses are host-specific: human flus stay with humans, dog flus with dogs. Cross-species jumps are the rare exception, not the rule.
Lice. Lice are species-specific too. Dog lice infest dogs, human lice infest humans, and the two don’t trade. Lice are also uncommon in dogs unless they’re kept in crowded conditions.
The one that keeps evolving: pox viruses
Mpox (the disease formerly called monkeypox) is the interesting edge case, because it runs the other direction, person to pet, rather than pet to person. It’s a virus that can cause fever, respiratory symptoms, and skin lesions, and it spreads through direct contact, respiratory droplets, and contaminated bedding and surfaces. There has been at least one documented case of infected owners passing it to their dog. If a dog is exposed or develops symptoms, the guidance has been to isolate and monitor the animal for about three weeks.
What’s new since this was written
Two things have moved. First, the name: in late 2022 the World Health Organization renamed monkeypox to mpox, largely to reduce stigmatizing and inaccurate associations with a particular region. If you’re searching for current guidance, “mpox” is the term that now surfaces it.
Second, the science on pets and pox viruses has firmed up. The first evidence of human-to-dog transmission of the virus was reported in The Lancet in August 2022, and it remains a genuine but rare event, a reverse-zoonosis, where the human is the source. Animal-health bodies including the World Organisation for Animal Health now track the disease in animals, and the current picture is unchanged in spirit from the original advice: the risk to and from ordinary pet dogs is low, isolation and monitoring are the response if exposure happens, and normal household hygiene covers most of it. As always, the least exciting measures do the most work: keep preventatives current, wash your hands, and get new skin lesions or wounds looked at early.
References
- Healthy Pets, Healthy People: Dogs, CDC
- Leptospirosis, CDC
- Zoonotic Diseases, World Organisation for Animal Health (WOAH)
- Mpox in Animals, World Organisation for Animal Health (WOAH)
- First Report of Human-to-Dog Transmission of Monkeypox Virus, The Lancet, August 2022
- About Mpox, CDC
- Raw or Undercooked Animal-Source Protein in Cat and Dog Diets, AVMA
