Veterinary Public Health Section

Zoönotic Diseases

Animals provide many benefits to humans — owning and caring for a pet can help increase fitness, lower stress, and bring happiness to humans. Viewing and safely interacting with animals outside of the home can also provide people of all ages with a chance to see and learn new things about nature.

Diagram depicting people (adults and child) and animals (dog, raccoon, chickens) and the exchange of germs between them

Unfortunately, animals can also be a source of illness and disease for humans. Zoönotic (zoe-uh-NAH-tik) diseases are infectious diseases that are shared between people and animals. Pets, livestock, and wild animals can carry germs that can spread to people through direct or indirect contact and make people sick. Even if an animal looks healthy, it can still spread germs that can cause disease.

How Zoönotic Diseases Spread

People can get zoönotic diseases in many different ways including:

From animal and insect bites
Eating foods that come from animals (like meat and dairy products)
Touching or handling items that had contact with animals or animal waste and then touching one’s eyes, nose, or mouth
Handling live or dead animals or their tissues and then touching one’s eyes, nose, or mouth

Contact with Animals

Direct contact with animals includes touching or petting animals, as well as bites and scratches from animals.

Indirect contact includes being in an area where animals are or were present, or touching something that has had contact with animals, such as food bowls, cages/pens, and animal bedding.

Outbreaks Associated with Live Animal Contact in California

Outbreaks of infectious diseases, such as salmonellosis and Shiga-toxin producing E. coli (STEC) infection, are sometimes associated with animals in California. The following list includes recent animal-associated outbreaks caused by germs from animals (for example, Salmonella) that affected California residents.

2023

Small Turtles – Salmonella Infections
Backyard Poultry – Salmonella Infections

2022

Pet Bearded Dragons – Salmonella Infections
Pet Bearded Dragons – Salmonella Infections
Backyard Poultry – Salmonella Infections

For more information about zoönotic disease outbreaks, see the U.S. Centers for Disease Control and Prevention (CDC) US Outbreaks of Zoonotic Diseases Spread Between Animals & People webpage.

Prevention

Some zoönotic diseases can be severe and even deadly, especially for very young children, older adults and seniors, and those with weakened immune systems. It’s important to protect your health when around animals or areas where animals are or have been present. To help reduce your risk of getting a zoönotic disease:

Keep your hands clean — always wash your hands after being around animals or areas where animals are active or kept.
Handle and prepare food safely.
Do not touch or approach wild animals or any animals that you do not know.
Use insect repellent to prevent bites from insects and ticks.
Be sure your pets get regular veterinary care.
Learn more about zoönotic diseases and how you can stay healthy around animals while at home or while traveling:

For more information about specific zoönotic diseases of concern in California, see the menu at the left of this page.
For a full list of zoönotic diseases, see the CDC Diseases That Can Spread Between People and Animals webpage.