Zoonotic diseases: protecting your family from illnesses pets can carry

Sharing a home with a dog or cat comes with a small, mostly manageable list of health risks that can pass between pets and people. Most families never think about it until a kid comes home with a strange rash or a vet mentions it in passing. This is general information, not a diagnosis — talk to your vet or physician about symptoms specific to you or your pet.

The risks worth knowing about aren’t exotic. They’re common, well understood, and mostly prevented by washing your hands, scooping the litter box regularly, and keeping vaccines and parasite prevention current.

The risks that actually come up for typical pet owners

Ringworm is one of the more common ones. Despite the name, it’s a fungal skin infection, not a worm. It spreads through direct contact with an infected pet or contaminated bedding and shows up as a circular, often itchy patch of skin on both pets and people. It’s treatable and not usually serious, but it does spread within a household if left unaddressed.

Puppies and kittens carry roundworms and hookworms, intestinal parasites, at high rates, and adult pets can pick them up too, usually through contaminated soil or feces. Kids are at higher risk here mainly because they’re more likely to play in dirt or grass and put hands near their mouths. Routine deworming and picking up waste promptly cut this risk significantly.

Tick-borne disease is a smaller but real concern in Colorado, particularly for pets that spend time in grassy or wooded areas. A tick can pass disease to a pet, and separately, ticks that end up on a person after riding in on a pet’s coat can pass disease to people too. Regular tick prevention on your pet and a quick check after time outdoors covers most of this.

Rabies is rare in pets today specifically because vaccination is required and widely followed, but it remains the most serious risk on this list if it does occur, since it’s almost always fatal once symptoms start. Keeping your pet’s rabies vaccination current is the single biggest thing you can do here.

Habits that lower the risk without much effort

None of the prevention here is complicated. It’s mostly about consistency.

Handwashing after handling pets, cleaning up waste, or gardening in areas pets use is the single most effective habit on this list, and it’s free. Keep your pet current on parasite prevention and deworming on the schedule your vet recommends for their age and lifestyle, since puppies, kittens, and outdoor cats generally need it more often than an adult indoor pet. Scoop litter boxes daily rather than every few days, since the parasite that causes toxoplasmosis becomes infectious after sitting for a day or more. Keep vaccinations current, especially rabies, which is both a legal requirement in Denver and genuinely the best protection against a rare but serious disease. And avoid letting pets lick open wounds, cuts, or a baby’s face, since it’s an easy way for bacteria to transfer even from a healthy-looking pet.

Who should be more careful

Most healthy adults face very low risk from normal pet ownership. A few groups warrant more caution:

Group	Why	What helps
Young children	More hand-to-mouth contact, less consistent handwashing	Supervise pet interactions, teach handwashing after play
Pregnant people	Toxoplasmosis risk from litter box exposure	Avoid scooping litter, or wear gloves and wash hands well
Immunocompromised family members	Lower ability to fight off infections that healthy people shed easily	Talk to a physician about specific precautions for your situation
Older adults with chronic illness	Slower recovery from minor infections	Same hygiene basics, with extra attention to bite and scratch care

If someone in your household falls into one of these groups, it doesn’t mean giving up the pet. It usually just means being a little more deliberate about litter box duty, handwashing, and keeping your pet’s preventive care on schedule.

When to loop in a professional

A vet can tell you what parasite prevention and deworming schedule makes sense for your specific pet, and a physician is the right person to ask about risk specific to a family member’s health situation, especially during pregnancy or with a weakened immune system. Bringing up zoonotic risk at a routine visit is a normal question to ask, not an overreaction. For more on general preventive care, the general veterinary care category page covers routine visit topics, and the homepage has additional guides. You can also see how this site evaluates providers on the methodology page.

Most households with pets never deal with any of this beyond a routine deworming pill or a reminder to wash hands. Knowing the short list of what actually matters means you can relax about the rest.