Pet Care

Zoonotic Diseases: What Pet Owners Should Know About Illnesses That Jump Species

Pet Care Editorial TeamStaff Writer · 10 min read · May 2, 2023

Zoonotic Diseases: What Pet Owners Should Know About Illnesses That Jump Species

In This Article

Some diseases can pass between animals and humans. Learn which ones are relevant to household pets and how basic hygiene reduces transmission risk.

Key Takeaways

Many common household pets can carry pathogens capable of infecting humans, even when the animals appear healthy.
Young children, older adults, pregnant individuals, and immunocompromised people face elevated risk from zoonotic exposure.
Routine veterinary care — including vaccinations, deworming, and parasite control — significantly reduces transmission risk.
Basic hygiene practices such as handwashing after animal contact are among the most effective protective measures available.
Reptiles and birds carry specific zoonotic risks that require extra precautions, especially in households with vulnerable members.
If you develop symptoms after contact with a pet, consult a healthcare professional and mention the exposure.

How Pathogens Move Between Animals and People

The term zoonosis covers a wide range of infections — bacterial, viral, parasitic, and fungal — that cross the biological boundary between humans and other animals. The U.S. Centers for Disease Control and Prevention (CDC) estimates that more than 6 out of every 10 known infectious diseases in people can be spread from animals, and roughly 3 in 4 new or emerging infectious diseases originate in animals.

For pet owners, the relevant pathogens are typically transmitted through one of these routes:

Direct contact: touching an animal's feces, urine, saliva, blood, or skin.
Bites and scratches: even minor wounds can introduce bacteria such as Pasteurella or, in rare cases, rabies virus.
Fomite or environmental contact: touching contaminated cage surfaces, bedding, water bowls, or soil.
Vector transmission: fleas or ticks that feed on infected animals and then bite humans, potentially transmitting diseases like Lyme disease or cat scratch disease (caused by Bartonella henselae).

Understanding these pathways is the foundation for interrupting them. See our guide to parasite prevention for a deeper look at how fleas and ticks are managed in household pets.

6 in 10

Known infectious diseases that can spread from animals

According to the U.S. Centers for Disease Control and Prevention (CDC), more than 60% of known human infectious diseases have an animal origin.

3 in 4

New or emerging infectious diseases linked to animals

The CDC estimates that approximately 75% of new or emerging infectious diseases in people originate in animals, underscoring the broad relevance of zoonotic disease awareness.

~11%

US reptile-owning households with Salmonella exposure risk

Research published in public health literature has consistently identified reptile ownership as a significant risk factor for household Salmonella exposure, particularly affecting young children.

Common Zoonotic Diseases Linked to Household Pets

Several zoonotic diseases are directly relevant to US pet households. The following are among the most frequently documented:

Salmonellosis

Caused by Salmonella bacteria, this infection is strongly associated with reptiles (turtles, geckos, iguanas) and poultry. Animals shed the bacteria in their feces and can contaminate their entire environment. Symptoms in people include diarrhea, fever, and stomach cramps. The CDC specifically advises against keeping reptiles in homes with children under five, pregnant individuals, or immunocompromised people.

Ringworm

Despite the name, ringworm is a fungal infection caused by dermatophyte fungi — not a worm. Dogs, cats, and guinea pigs can carry it and transmit it through direct skin contact. It appears as a circular, scaly rash in humans and is treatable, but spreads easily in households with children.

Toxoplasmosis

Caused by the parasite Toxoplasma gondii, this disease is associated primarily with cats, which are the definitive host. Humans most commonly acquire it by accidentally ingesting oocysts shed in cat feces — typically through contaminated soil, unwashed produce, or improper litter box handling. Toxoplasmosis poses particular concern during pregnancy, where it can affect fetal development. Pregnant individuals should consult their obstetrician about safe litter-box management practices.

Cat Scratch Disease

Caused by the bacterium Bartonella henselae, this infection is transmitted when an infected cat's scratch or bite introduces bacteria into the skin. Fleas play a key role in maintaining the bacterium in cat populations. Most healthy adults recover without treatment, but immunocompromised individuals can experience more serious complications.

Psittacosis

Also known as parrot fever, this bacterial infection (caused by Chlamydia psittaci) affects birds in the parrot family — including parakeets, cockatiels, and macaws — as well as other birds. Humans can inhale the bacteria through dried feces or respiratory secretions. Symptoms resemble pneumonia and require antibiotic treatment.

Who Is Most Vulnerable — and What That Means Practically

Most healthy adults who practice good hygiene are at relatively low risk from household pet zoonoses. However, certain groups face meaningfully elevated risk and should take additional precautions:

Children under five — developing immune systems and hand-to-mouth behavior increase exposure risk.
Adults over 65 — age-related immune changes can make infections more severe.
Pregnant individuals — infections like toxoplasmosis can have serious consequences for fetal health.
Immunocompromised individuals — those undergoing chemotherapy, living with HIV, or taking immunosuppressive medications should discuss pet ownership precautions with their healthcare provider.

If someone in your household falls into one of these categories, that doesn't necessarily mean pets are off-limits — but it does call for a conversation with both a veterinarian and a physician to determine appropriate precautions. This consideration also extends to pet choice: a dog with a current vaccination and parasite prevention schedule is generally a lower-risk companion than an unvaccinated reptile in the same household.

Talk to Your Vet at Every Wellness Visit

Inform your veterinarian about anyone in the household who is pregnant, immunocompromised, very young, or elderly. Your vet can tailor preventive care recommendations — such as specific parasite control protocols or hygiene guidance — based on the full household context, not just the pet's individual health.

Practical Prevention: What Veterinary Guidance Recommends

The good news is that consistent, straightforward habits dramatically reduce the risk of zoonotic transmission. Veterinary and public health consensus points to the following core strategies:

Prioritize Preventive Veterinary Care

Keeping pets current on vaccines (especially rabies), routine deworming, and flea and tick prevention directly reduces the likelihood that pets carry or shed zoonotic pathogens. Regular wellness exams also catch subclinical infections early. Our article on gaps in pet health routines explains why skipping these steps can compound over time.

Practice Consistent Hand Hygiene

Wash hands with soap and water — not just hand sanitizer — after handling any animal, their food, their waste, or their environment. This single step interrupts the most common transmission routes. Teach children this habit before and after every pet interaction.

Handle Waste Carefully

Use gloves when cleaning litter boxes, cages, or aquariums, and wash hands afterward regardless. Pregnant individuals should ideally have someone else manage litter box duties. Dispose of pet waste promptly and avoid letting it accumulate in areas where children play.

Avoid High-Risk Behaviors

Do not allow pets to lick open wounds, eyes, or mouths. Discourage rough play that leads to bites or scratches, particularly with young children. Keep pet feeding areas separate from food preparation surfaces.

Know Your Pet's Species-Specific Risks

Reptile owners should treat every animal as a potential Salmonella carrier and apply strict post-handling hygiene. Bird owners should monitor for respiratory symptoms in birds and in themselves. Consulting your vet about species-specific disease risks when you first acquire a new type of pet is a simple, high-value step.

For a broader look at how pet health decisions interact, see our article on common pet health misconceptions that veterinarians regularly address.

This article is for general informational and educational purposes only and is not a substitute for professional medical or veterinary advice. If you believe you or a family member has contracted a zoonotic illness, consult a licensed healthcare provider. For questions about your pet's health or disease prevention protocols, speak with a licensed veterinarian.

Frequently Asked Questions

Can a healthy-looking pet still spread zoonotic disease?

Yes. Many animals carry zoonotic pathogens without showing any signs of illness — a state called asymptomatic carriage. For example, reptiles commonly harbor Salmonella bacteria and appear completely healthy. This is why hygiene practices matter regardless of whether your pet seems sick.

Which pets carry the highest zoonotic disease risk?

Reptiles (turtles, lizards, snakes) and birds carry some of the most well-documented zoonotic risks, including Salmonella and Psittacosis respectively. Dogs and cats also carry various transmissible pathogens, but routine vaccination and parasite prevention substantially reduce those risks. No pet is entirely risk-free.

How does zoonotic disease most commonly spread from pets to people?

The most common routes are direct contact with an animal's feces, urine, saliva, or skin; bites and scratches; and indirect contact via contaminated surfaces or water. Vector-borne transmission — through fleas or ticks that move between animals and people — is also a significant route for several diseases.

Are children more at risk from pet-related zoonotic diseases?

Children under five are considered a high-risk group because their immune systems are still developing and they are more likely to put hands in their mouths after touching animals. Pediatricians and veterinarians generally recommend keeping young children away from reptiles and supervising all pet interactions closely.

Does my pet's vaccination schedule protect me from zoonotic disease?

Keeping pets up to date on core vaccines — particularly rabies — directly reduces the risk of certain zoonotic infections. Vaccinations protect the animal from becoming a reservoir for disease, which in turn protects the people they live with. Regular vet visits are a core part of household disease prevention.

What should I do if I think I contracted something from my pet?

Contact a licensed healthcare provider promptly and tell them about the animal exposure, including the species, any bites or scratches, and recent activities (such as cleaning a litter box or handling reptiles). Do not attempt to self-diagnose or treat. Your vet should also be informed so your pet can be evaluated.

Pet Care Editorial Team

Staff Writer

Pet Care Editorial Team is the collective byline for our editorial team and contributor network. Articles published under this byline or an editorial pen name are researched, written, and reviewed according to our editorial standards for clarity, consistency, and independence before publication.