Key Takeaways
- Zoonotic diseases can pass between pets and people, but most risks are manageable with routine precautions.
- Handwashing after pet contact is one of the single most effective preventive measures available.
- Keeping pets current on vaccines and parasite prevention significantly reduces household transmission risk.
- Immunocompromised individuals, children, and pregnant people face elevated risk and should consult a physician.
- Raw pet food, bites, scratches, and fecal contact are the most common transmission routes in home settings.
When Pet Love Comes With a Health Footnote
Sharing your home with a dog, cat, bird, or reptile brings genuine well-being benefits — but it also creates the possibility of disease crossing the species barrier. These are called zoonotic diseases (from the Greek zōon, meaning animal), and the U.S. Centers for Disease Control and Prevention estimates that more than 6 out of every 10 known infectious diseases in people can be spread from animals.
That statistic sounds alarming, but it shouldn't be. The everyday risk to healthy adults living with well-cared-for pets is generally low. What matters is understanding how transmission occurs and which straightforward practices interrupt it. The list below covers the zoonoses most relevant to US pet owners, with practical, vet-informed context for each. As always, this article is general health information — not a substitute for guidance from your physician or veterinarian, particularly if anyone in your household is pregnant, immunocompromised, elderly, or under age five.
For a broader look at building your pet's defenses from the start, see our new pet veterinary care roadmap.
Ringworm (Dermatophytosis)
Despite its name, ringworm is not a worm — it's a fungal infection caused by Tinia species that infects skin, hair, and nails. Cats, especially kittens, are a common reservoir. Transmission happens through direct skin contact with an infected animal or contaminated surfaces.
Precautions: Have pets examined by a veterinarian if you notice circular, scaly hair-loss patches on their skin. Avoid handling strays without gloves. Wash hands and forearms thoroughly after contact with any new or symptomatic animal. Ringworm in people is treated with antifungal medications — see a healthcare provider for diagnosis.
Ringworm spreads through direct skin contact with infected animals — gloves and handwashing interrupt most transmission.
Toxoplasmosis
Toxoplasma gondii is a single-celled parasite whose definitive host is the cat family. Infected cats shed oocysts (infectious eggs) in their feces for a short window after first infection. The parasite is typically harmless to healthy adults but poses serious risks during pregnancy, potentially causing miscarriage or congenital complications.
Precautions: Pregnant individuals should have someone else handle litter box duties or use disposable gloves and wash hands thoroughly. Clean litter boxes daily — oocysts take 1–5 days to become infectious after shedding. Indoor cats that don't hunt or eat raw meat rarely become infected. Meat, not cat contact, is actually the most common source of toxoplasmosis in the US population.
For pregnant individuals, daily litter box cleaning by another household member dramatically reduces toxoplasmosis exposure.
Salmonellosis
Salmonella bacteria can be carried by reptiles (turtles, lizards, snakes), birds, and some mammals without the animal appearing ill. Transmission occurs via fecal-oral routes — touching a contaminated surface and then the mouth. Raw pet diets have also been associated with household Salmonella contamination.
Precautions: Always wash hands after handling reptiles, their enclosures, or their food and water dishes. Keep reptiles out of kitchens and food-preparation areas. The CDC specifically advises against keeping turtles with shells under four inches in households with children under five. If feeding a raw diet, handle it with the same hygiene practices used for raw human food.
Reptiles can carry Salmonella without symptoms — handwashing after every handling session is non-negotiable.
Campylobacteriosis
Campylobacter is a bacterial infection that causes diarrhea, cramping, and fever in people. Puppies and kittens — especially those recently acquired from shelters or pet stores — are more likely to shed the organism. Contact with pet feces, contaminated water, or raw pet food are the primary exposure routes.
Precautions: Wash hands after any pet waste contact. Scoop feces promptly. New puppies and kittens should be screened for intestinal pathogens as part of their first veterinary visits — a step covered in detail in our first-30-days veterinary roadmap. Avoid contact with pet stool if you are immunocompromised.
New puppies and kittens are disproportionately likely to shed Campylobacter — early vet screening helps catch this early.
Cat Scratch Disease (Bartonellosis)
Cat scratch disease is caused by the bacterium Bartonella henselae, transmitted through the scratch or bite of an infected cat, or when cat feces from infected fleas are rubbed into a wound. Most healthy adults develop a self-limiting illness (swollen lymph nodes, mild fever), but immunocompromised individuals can develop severe complications.
Precautions: Keep cats on year-round flea prevention — fleas are the primary source of Bartonella in cats. Wash scratches and bites immediately with soap and water. Avoid rough play that invites scratching, particularly with kittens. Do not allow cats to lick open wounds. Immunocompromised individuals should consult their physician about specific precautions.
Controlling fleas on your cat is the most upstream prevention against cat scratch disease in your household.
Rabies
Rabies is a fatal viral disease affecting the central nervous system. While documented human deaths from pet-transmitted rabies are rare in the US due to widespread pet vaccination, wildlife contact — and unvaccinated pets that encounter wildlife — remain the primary risk pathway. Bats, raccoons, skunks, and foxes are the principal reservoir species in the US.
Precautions: Keep dogs and cats current on rabies vaccination — it is legally required in most US states. Report any contact with wildlife, especially bats, to your local health department or physician promptly. Post-exposure prophylaxis (PEP) is highly effective when given quickly, so don't wait to seek care after a potential exposure. Never handle wild animals with bare hands.
Keeping pets vaccinated against rabies is legally mandated in most US states and remains the cornerstone of human protection.
Intestinal Parasites (Roundworms and Hookworms)
Common intestinal parasites such as Toxocara (roundworms) and Ancylostoma (hookworms) shed eggs in pet feces that can survive in soil for months to years. Children playing in contaminated soil and adults gardening without gloves are at greatest risk. Larval migration in humans can, in rare cases, cause eye or organ damage (visceral larva migrans).
Precautions: Keep pets on veterinarian-recommended deworming and broad-spectrum parasite prevention programs. Pick up pet feces promptly — before eggs have time to become infectious. Cover sandboxes when not in use. Wear gloves when gardening. Children should wash hands after outdoor play. Annual fecal tests for pets help confirm parasite status even when no symptoms are visible.
Prompt feces removal and routine deworming together prevent most household exposure to intestinal parasite eggs.
Building Everyday Habits That Keep Everyone Safer
No single precaution eliminates all zoonotic risk, but a consistent combination of habits makes transmission genuinely unlikely for most households. Handwashing with soap and water for at least 20 seconds after handling pets, their food, or their waste is foundational. Keeping your pet's vaccines and parasite prevention current — flea, tick, and heartworm — removes several transmission pathways at once. See our guide on preventive care vs. reactive treatment for perspective on why routine prevention carries long-term value.
Scoop litter boxes and pick up dog waste promptly and wear gloves when gardening where animals may have defecated. Avoid allowing pets to lick open wounds or mucous membranes. Treat bites or scratches promptly with soap and water and consult a healthcare provider if redness, swelling, or fever develops. Anyone in a higher-risk group — including those managing chronic illness — should speak with both their physician and their veterinarian about tailored precautions rather than relying solely on general guidance.
A Simple Habit With Outsized Impact
Handwashing is consistently identified by public health authorities as the single most effective individual behavior for reducing zoonotic transmission risk. Use soap and running water for at least 20 seconds after handling pets, their food or treats, their bedding, or their waste. Hand sanitizers are better than nothing when soap isn't available, but soap and water is preferred for removing many pathogens.
This article is for general informational purposes only and does not constitute medical or veterinary advice. Consult a qualified healthcare provider or licensed veterinarian for guidance specific to your circumstances.