Can I get sick from my dog or cat?

Yes, but the risk for healthy adults is generally low with basic hygiene. Certain infections -- ringworm, roundworm, salmonella, cat scratch disease -- can pass from pets to people. People with weakened immune systems, young children, and pregnant women face higher risk from some zoonotic infections. The key is knowing what they are and taking simple precautions.

What is the most common zoonotic disease from cats?

Cat scratch disease (caused by Bartonella henselae bacteria) is one of the most commonly reported. It is transmitted through scratches, bites, or contact with flea dirt on a cat's claws. Most healthy adults experience mild symptoms or none at all. People with suppressed immune systems can develop more serious complications.

Can roundworms from pets infect people?

Yes. Toxocara, the roundworm that infects dogs and cats, can pass to people through contact with contaminated soil or feces. Children are at higher risk because of hand-to-mouth behavior. Most cases are mild or asymptomatic in adults. In rare cases, larvae migrate to the eye or central nervous system. Regular deworming of pets is the key preventive measure.

Does having a pet vaccinated reduce my risk?

For rabies specifically, yes -- your pet's vaccination is your primary protection against rabies exposure. For most zoonotic diseases, vaccination of the pet does not directly affect transmission risk, but regular vet care (which includes parasite prevention and deworming) does.

Diseases pets can pass to people: what Denver pet owners should know

By Maya Krishnan · Updated 2026-06-17

This guide provides general health information for reference. It is not medical advice. If you believe you or a family member may have contracted a zoonotic infection, consult a physician.

The most relevant risks for Denver pet owners

Zoonotic diseases sound alarming but the practical risk for most healthy adults who follow basic hygiene is low. Context matters: contact with a healthy, vaccinated, parasite-free pet is very different from contact with a stray animal or one with unknown health history.

The infections below are the ones most relevant to dog and cat owners in Colorado.

Common zoonotic risks by pet type

Infection	Source	Transmission	Risk level for healthy adults	Prevention
Ringworm	Cats and dogs (it is a fungus, not a worm)	Direct contact with affected skin or coat	Low to moderate; very contagious skin-to-skin	Treat infected pet promptly; wash hands after handling
Cat scratch disease	Cats (Bartonella via fleas)	Scratch or bite from an infected cat	Low for healthy adults; higher for immunocompromised	Flea control; wash bites and scratches immediately
Toxoplasmosis	Cats (from ingesting prey)	Contact with cat feces, undercooked meat	Low for healthy adults; significant risk during pregnancy	Pregnant women: avoid litter box; wash hands after gardening
Roundworm (Toxocara)	Dogs and cats	Contact with contaminated soil or feces	Low in adults; higher risk for children	Regular deworming; supervise children in soil; wash hands
Salmonella	Reptiles, sometimes dogs/cats on raw diets	Fecal-oral	Low with hygiene; higher for children and immunocompromised	Wash hands after handling reptiles; caution with raw pet food
Leptospirosis	Dogs (from wildlife, water)	Contact with infected urine or water	Moderate; more common in hunters, outdoor workers	Vaccinate dogs in at-risk situations; avoid contact with potentially contaminated water
Rabies	Any mammal (in Colorado: bats, skunks, foxes, raccoons)	Bite from infected animal	Very low if pet is vaccinated	Keep pet vaccines current; avoid contact with wildlife

Who faces higher risk

Most healthy adults are at low risk from their own well-cared-for pets. The following groups should take extra care:

Pregnant women: Toxoplasmosis is a significant concern during pregnancy. Avoid cleaning the litter box, or use gloves and wash hands thoroughly.
Infants and young children: Higher risk from roundworm due to hand-to-mouth behavior. Supervise interaction with animals and handwashing after play.
People with immune system conditions: HIV, cancer treatment, organ transplant recipients. These individuals should consult their physician about specific precautions with pets.
The elderly: Similar to immunocompromised; immune function declines with age.

A parent helping a young child wash their hands at a sink after playing with the family dog in a bright Denver kitchen

Practical steps that cover most risks

Keep pets current on vaccines, especially rabies.
Use veterinarian-recommended parasite prevention (fleas, ticks, and intestinal parasites).
Have your pet’s feces checked for parasites annually.
Wash hands after handling pets, cleaning litter boxes, or picking up after dogs.
Clean bites and scratches from any animal immediately with soap and water.
If your pet shows signs of illness — skin lesions, diarrhea, respiratory symptoms — get them evaluated promptly.

Most zoonotic infections are prevented by the same habits that make for a well-cared-for pet. Regular vet care, parasite control, and basic hand hygiene close the majority of the risk.

Browse Denver veterinarians on the home page and see our ranking method for how we evaluate clinics in this directory.

FAQ

Can I get sick from my dog or cat?: Yes, but the risk for healthy adults is generally low with basic hygiene. Certain infections -- ringworm, roundworm, salmonella, cat scratch disease -- can pass from pets to people. People with weakened immune systems, young children, and pregnant women face higher risk from some zoonotic infections. The key is knowing what they are and taking simple precautions.
What is the most common zoonotic disease from cats?: Cat scratch disease (caused by Bartonella henselae bacteria) is one of the most commonly reported. It is transmitted through scratches, bites, or contact with flea dirt on a cat's claws. Most healthy adults experience mild symptoms or none at all. People with suppressed immune systems can develop more serious complications.
Can roundworms from pets infect people?: Yes. Toxocara, the roundworm that infects dogs and cats, can pass to people through contact with contaminated soil or feces. Children are at higher risk because of hand-to-mouth behavior. Most cases are mild or asymptomatic in adults. In rare cases, larvae migrate to the eye or central nervous system. Regular deworming of pets is the key preventive measure.
Does having a pet vaccinated reduce my risk?: For rabies specifically, yes -- your pet's vaccination is your primary protection against rabies exposure. For most zoonotic diseases, vaccination of the pet does not directly affect transmission risk, but regular vet care (which includes parasite prevention and deworming) does.