CDC would like to thank MAJ Justin Schlanser, DVM, MPH, Diplomate of the American College of Veterinary Preventive Medicine, for his careful review of these pages.
Wildlife includes any undomesticated animal living in the wild, including
those hunted for food, sport, or profit. Many people enjoy watching wildlife, and studies have shown that positive encounters with wildlife can have profound, life-changing effects on people. If you and your pets spend time outdoors around wildlife, you need to be aware of the diseases that can spread from wildlife to you and your pets.
Because wild animals can carry diseases without appearing to be sick, it is important to enjoy wildlife from a distance. Close contact with wildlife or their urine or droppings can spread these diseases to people and pets.
To protect yourself and your family from getting sick:
- Avoid hand-feeding wildlife.
- Avoid playing or working in areas where there are wildlife droppings.
- Leave orphaned animals alone. Often the parents are close by and will return for their young.
- Always wash your hands and the hands of children with running water and soap after working or playing outside, especially in areas where wildlife have been spotted.
By following some simple health tips, you are less likely to get sick from wildlife in the United States.
The most common diseases associated with wildlife that can cause human illness are:
Though it very rarely happens, people can become infected when they handle infected fish or accidentally swallow contaminated food or water. If these germs are swallowed, Aeromonas infections can cause nausea, vomiting, and diarrhea. Skin infections can happen if the bacteria get into open wounds or scrapes. More severe disease can happen in children or people with weakened immune systems.
Practicing healthy habits, including hand washing, will reduce the risk of Aeromonas infection.
Anthrax is a serious but rare disease in the United States. The symptoms of anthrax depend on the route of infection and can take anywhere from 1 day to more than 2 months to appear. All types of anthrax have the potential, if untreated, to spread throughout the body and cause severe illness and even death. To prevent anthrax, be aware of areas where anthrax is present and wear gloves when handling animal carcasses from those regions. Use care when processing bloated or swollen carcasses so that accumulated gasses blow away from you when the carcass is opened.
If a person or dog ingests the eggs, the worm larvae then hatch inside them and can migrate through the body. Human infections are rare but can be severe if the parasites invade the eye (ocular larva migrans), organs (visceral larva migrans), or brain (neural larva migrans).
Raccoon roundworm can be prevented by avoiding areas frequented by raccoons. If you need to clean raccoon droppings up, wear gloves and use caution so as not to kick up dust. Always wash your hands after working or playing in dirt.
A person with botulism can develop double vision, blurred vision, drooping eyelids, and paralysis, which can result in death. People are commonly exposed through the environment or contaminated food, such as smoked fish products. To protect yourself from botulism, avoid fishing in areas where there are dead fish or waterfowl and cook all fish thoroughly. Anyone who thinks they may have botulism should seek emergency medical care.
People who hunt or eat fresh game meat are at highest risk for contracting brucellosis. They may be exposed through skin wounds while dressing a carcass or by eating undercooked meat. People who are infected with brucellosis will usually become sick within 6-8 weeks of exposure. Sick people will have flu-like symptoms that last 2-4 weeks. Sometimes brucellosis can become a chronic illness that can be difficult to treat.
Prevent brucellosis by wearing gloves while handling fresh carcasses and thoroughly cooking any meat that will be eaten.
Most people do not become sick with cryptococcosis, but people with weakened immune systems may be at risk. Signs of disease include headaches, fever, cough, shortness of breath, and night sweats.
Prevent cryptococcosis by avoiding enclosed areas where pigeons or other wild birds roost.
This disease is most common among people who raise deer or who have contact with fawns. People who handle an infected animal may get pus-filled blisters on their hands and arms. These sores are usually not painful but can develop into shallow, red ulcers that scar.
Wear gloves and protective clothing when working with any animals, especially those with the classic “paintbrush” matted hair appearance, to reduce the risk of getting this disease.
Although the Echinococcus parasite invades many different organs of the body, most people who are infected with the disease will not have any signs of illness for years. Symptoms start when the slow-growing cysts become large enough to press on the organs they have invaded. The tapeworms grow slowly in several different organs of the body but are most commonly found in the liver and lungs.
Prevent echinococcosis by avoiding stool of wild canids, thoroughly cooking game meat, and practicing healthy habits, including hand washing.
People can become infected by accidentally swallowing contaminated water or through handling infected fish. Affected people commonly get nausea, vomiting, and/or diarrhea. People with weak immune systems may also be at risk for more serious disease.
Wash your hands before and after handling fish to reduce the risk of edwardsiellosis.
People, especially fish handlers, can become infected through open wounds on their hands. Affected people will usually develop a warm, raised, red, and intensely itchy area of skin at the site of the contaminated wound. If the infection spreads from the skin to deeper tissues, arthritis or more serious signs of illness (fever, weakness, muscle aches, headaches, etc.) may develop.
People who handle fish regularly should wear gloves and wash their hands often to reduce the risk of this disease.
In people, the symptoms of giardiasis may include diarrhea; gas; greasy stools; abdominal pain; nausea; and vomiting. Symptoms can last 1–2 weeks.
To avoid Giardia infection, hikers and backpackers should always treat water before offering it to their pets or drinking it themselves. People should also wash their hands often and use caution when swimming or wading in potentially contaminated ponds or lakes to avoid swallowing the water.
Early signs in people include fever, headache, muscle aches, vomiting, diarrhea, abdominal pain, dizziness, and chills.
Follow CDC’s cleaning guidelines for cleaning areas that may have a rodent infestation, and air out unused buildings before entering.
Very few people become infected with histoplasmosis. People who do become sick tend to develop pneumonia-like symptoms (fever, chest pains, and a dry or nonproductive cough) within 1–3 weeks after exposure. Infants, older people, and those with weakened immune systems are more susceptible to the fungus and might develop more serious illness.
People with weak immune systems should avoid activities such as disturbing material where there are bird or bat droppings, cleaning chicken coops, exploring caves, and cleaning, remodeling, or tearing down old buildings.
People who become infected with leptospirosis might not have any symptoms of the disease. Others will have nonspecific flu-like symptoms (fever, headache, chills, vomiting, rash) within 2–7 days after exposure. These symptoms usually resolve without medical treatment but can reappear and lead to more severe disease (yellow skin and eyes, rash, kidney or liver failure, meningitis).
Some ways to prevent leptospirosis from wildlife are to avoid contact with environments potentially contaminated with animal urine and to avoid swallowing water from lakes, rivers, or swamps while swimming.
Infected people will typically have a red “bull’s eye” rash (erythema migrans) at the site of the tick bite that appears about 7 days after being bitten. Flu-like symptoms quickly follow the rash. If not treated, this disease can spread to other parts of the body and cause symptoms such as arthritis and loss of facial muscle tone (Bell’s palsy).
Lyme disease can be prevented by avoiding exposure to ticks, using a tick repellent, and by finding and removing ticks from your pets and your family as soon as possible after returning from a tick-infested area.
Human infections with LCMV are rare. Symptoms are similar to those of the common flu (fever, stiff neck, loss of appetite, muscle aches, headache, nausea, and vomiting) and often occur 1–2 weeks after exposure.
Prevent LCMV infection by avoiding contact with wild rodents and their droppings.
Though infection in humans is rare, people can become sick with mycobacteriosis after coming into contact with contaminated water through minor cuts and skin abrasions. People with this disease, commonly known as “fish tank granulomas,” develop warm raised, red areas of the skin. Skin lesions can leave long-lasting scars.
Reduce the risk for mycobacterium by washing your hands after handling reptiles, amphibians, and fish.
People most often become infected with plague through flea bites or from contact with body fluids of infected animals. Hunters may be at increased risk. Bubonic plague is the most common form of plague that affects people. Symptoms include a sudden onset of high fever, chills, headache, malaise, and swollen glands (lymph nodes). The other two forms of plague, septicemic and pneumonic, cause more severe disease.
Plague can be prevented by keeping fleas away from your pets and family and by wearing gloves while handling or skinning potentially infected animals.
The first symptoms in humans can start days to months after exposure and include generalized weakness, fever, and headache. Within a few days symptoms will progress to confusion, anxiety, behavioral changes, and delirium.
If you have been bitten by a wild animal that wasn’t acting normal, contact your health care provider right away for treatment. Once symptoms appear, it is almost always too late for treatment.
In people infected with rat-bite fever, signs range from flu-like symptoms and a rash to more severe infections of the joints, liver, heart, lungs, brain, and blood, if left untreated.
Prevent Rat bite fever from wild rodents by avoiding contact with wild rodents and their urine.
People who are infected with RMSF generally start getting sick 2–14 days after exposure. Symptoms may include fever, rash, headache, nausea, vomiting, abdominal pain, and muscle pain. RMSF can develop into a serious illness if not promptly treated.
Rocky Mountain spotted fever disease can be prevented by avoiding exposure to ticks, using a tick repellent, and by finding and removing ticks from your pets and your family as soon as possible after returning from a tick-infested area.
People exposed to Salmonella might have diarrhea, vomiting, fever, or abdominal cramps. Infants, elderly persons, and people with weakened immune systems are more likely than others to develop severe illness.
Prevent salmonellosis by avoiding stool of wild animals, thoroughly cooking game meat, and practicing healthy habits, including hand washing.
People infected with Trichinella can have a variety of symptoms depending on the amount of parasite ingested and how strong their immune system is. The first symptoms of trichinellosis include nausea, vomiting, diarrhea, and abdominal pain. Infected people may then develop facial swelling and flu-like symptoms such as headache, fever, chills, and muscle pain. In very severe infections, people can lose control of their movements and have heart and breathing problems. Trichinella can cause death if severe infections are left untreated.
Prevent trichinellosis from wildlife by thoroughly cooking game meat.
People can get tuberculosis if they ingest undercooked meat, accidentally inhale the bacteria, or are infected through skin cuts or scrapes. Depending on the route of infection, people may have sores; swollen lymph nodes; difficulty breathing; weight loss; night sweats; fever; or intestinal upset.
Avoid tuberculosis from wildlife by thoroughly cooking meat and by washing your hands after handling wildlife.
People exposed to tularemia can have a variety of symptoms ranging from fever, chills, headache, and muscle aches to skin ulcers; swollen and painful lymph nodes; inflamed eyes; sore throat; mouth sores and diarrhea. They may also develop pneumonia.
People exposed to an infected animal should be seen by their doctor immediately because treatment works best when started early.
You can reduce your risk of tularemia by handling dead animals with gloves, cooking game meat thoroughly, wearing insect repellent, and when possible, avoiding mowing over dead animals during outside work.
It is very rare for people to get vesicular stomatitis. Infections can occur when people handle sick animals or contaminated tissues and blood from sick animals. Infected people may have a variety of symptoms ranging from no signs of illness to flu-like symptoms and blisters.
Reduce the risk for Vesicular stomatitis by washing your hands after handling affected wildlife.
In people, Vibrio can cause nausea, vomiting, and diarrhea. Some types of Vibrio can also cause skin infections from contact with contaminated water.
People can prevent vibriosis infections by eating cooked fish and shellfish and by avoiding exposure of open wounds or broken skin to warm salt or brackish water, and avoiding raw shellfish harvested from such waters.
Most people who become infected with WNV do not have any signs of illness; however, people who do become ill usually have flu-like symptoms. A small percentage of people with WNV infection develop a more serious neurologic illness, such as encephalitis or meningitis (inflammation of the brain and surrounding tissues).
Prevent West Nile Virus by using mosquito repellents, wearing long-sleeved shirts and long pants, and limiting outdoor exposure from dusk to dawn. Using air conditioning, installing window and door screens, and reducing mosquito breeding sites, can further decrease the risk for WNV exposure.
Wildlife should always be enjoyed from a distance. If you are close enough that
the animal changes its behavior (for example, stops eating or runs away), you are too close! Wild animals can carry diseases but not appear to be sick at all, so staying away is the safest way to enjoy viewing wildlife. Follow these simple tips to help protect your family and pets from getting diseases from wildlife. Additional tips and information about outdoor safety and disease control can be found under “More Information.”
- Keep windows and doors closed or screened and cover any holes or openings to prevent bats, rodents, or other wild animals from entering your home, church, school, or other buildings.
- Clean up trash around your home and keep your garbage cans closed. Garbage and trash can attract unwanted visits from wildlife.
- Do not leave food (bait) outside to attract animals to your backyard. This brings the animals closer together and close to you, and this makes it easier for disease to spread.
- Keep compost and wood piles at least 100 feet away from buildings to help reduce rodent infestations in the building.
- Make sure pets do not have access to stagnant water sources (ponds, bird baths, etc.) that are also used by wildlife.
- Find rodent- and bat-proofing information under the More Information tab.
- Teach children to never handle unfamiliar animals, wild or domestic,
even if they appear friendly or harmless.
- Do not touch or pick up dead animals with your bare hands. Consider calling animal control to remove any dead animals.
- Never adopt wild animals or bring them into your home. Do not try to save or rescue wild animals. If you have already found an animal, refer to the National Wildlife Rehabilitator’s Association’s Help! I’ve found an animal pageexternal icon.
- If an animal appears sick or hurt, call animal control to help. Do not touch young animals that appear to be abandoned. Often their parents are close by waiting for you to leave before they return to their young.
- Protect wildlife in your national parks and local recreational areas by staying on trails and following visitor guidelines, including those for trash disposal.
- Make washing your hands a routine practice before eating or drinking
and whenever you return from outside.
- Take care of bites and scratches:
- Wash wounds well with soap and running water.
- Contact your health care provider right away.
- If you seek medical attention, make sure to tell them if you have had exposure to wildlife.
- Keep bugs away:
- Use a mosquito and tick repellent when spending time outdoors.
- Use a monthly flea and tick preventive on your pets.
- Ask your veterinarian how to protect your pets from wildlife diseases such as rabies, leptospirosis, and giardia.
- Call animal control right away if an animal, wild or domestic, is acting strangely or out of character.
Rabies (For Kids)
CDC site especially designed for children
World Rabies Dayexternal icon
Bats and Rabies
CDC rabies site
CDC Rabies site: podcasts, videos, eCards, and more
Rodent and bat control
CDC Rodents site
Keeping Bats Out Of Your House
CDC Rabies site
Disease Vectors and Pests
CDC Healthy Housing Reference Manual; highly detailed
CDC comprehensive site
CDC BAM site
Camping Health and Safety Tips
CDC Family Health site
Tick Management Handbook pdf icon[PDF – 71 pages]external icon
CDC and Connecticut Agriculture Experiment Station
Protect Yourself from Ticks and Mosquitos
CDC NIOSH Fast Facts
It’s Open Season On Ticks [ PDF – 2 pages ]
CDC Ticks site
CDC; How foxes, raccoons, and bats play an important role in the ecology of infectious diseases, such as rabies
CDC Kidtastics podcast
Alexander KA, Pleydell E, Williams MC, Lane EP, et al. Mycobacterium tuberculosis: An Emerging Disease of Free-Ranging Wildlife. Emerging Infectious Diseases[serial on the Internet]. 2005 Jun [Cited Sep 18, 2015].
Bird feeder Maintenance and Hygieneexternal icon
National Audubon Society
Disease Precautions for Huntersexternal icon
American Veterinary Medical Association: highly detailed recommendations
Help! I’ve Found An Animalexternal icon!
National Wildlife Rehabilitators Association: What to do with orphaned wildlife
Raccoon Latrines: Identification and Clean-up [ PDF – 1 pages ]
CDC Baylisascaris Infection site