Living with Wildlife
Wildlife Diseases
Some diseases can be passed between wildlife, pets and people. The best way to prevent exposure to any wildlife diseases is to avoid approaching and handling wild animals.
If your pet has had contact with a skunk, bat, fox, prairie dog, raccoon or coyote, notify your veterinarian and your local health department. Domestic animals such as dogs, cats, cattle and horses can become infected if they touch or are bitten by a sick animal.
Diseases in Humans and Pets
Rabies
Rabies is a virus that attacks the brains of mammals. It’s transmitted most often when an infected animal bites another, and virus-containing saliva gets into the wound; it can also enter through mucous membranes like the eyes, nose and mouth. Bats and skunks are the main sources of rabies in Colorado, but it’s less common in other animals and is, overall, very rare in the state.
If you or your pet suffers a bite or a scratch, or has some other physical contact with a wild animal, contact your doctor or veterinarian immediately — a post-exposure vaccination may be necessary.
If a human or animal is exposed to rabies and does not receive treatment, the infection will be fatal. All pets should be vaccinated against rabies as a precaution.
What to Look For in Animals
- Aggression, no fear of humans, nonreactive if paralysis has set in
- Disorientation, lethargy
- Loss of interest in food or water
- Difficulty walking (signs of paralysis, lack of muscle coordination)
- Excessive salivation
What to Look For in Humans
- Pain, burning and numbness at the site of infection
- Inability to sleep
- Irritability
- Muscle spasms of the throat and difficulty swallowing
- Convulsions may occur, followed by unconsciousness and death.
Plague
Plague can be transmitted by contact with contaminated fluids or body parts, by breathing in infectious droplets, or by fleas bites. Usually, a plague-transmitting flea targets one species as its “natural host”: different kinds of fleas specialize in prairie dogs, wild cats, mice, ground squirrels and chipmunks. Fleas can be a “vector” of plague, meaning they pass it from one host to another.
Humans and pets can become infected through flea bites, and infections can be fatal if not treated promptly. Contact your physician immediately if you feel ill with flu-like symptoms following contact with wild mammals or fleas.
What to Look For in Animals
- Swollen lymph nodes on pet cats
- Fever or other general signs of illness in pet dogs or other animals with access to prairie dog habitat
- Contrary to popular belief, prairie dogs do get sick if infected with plague. If you notice a prairie dog colony has “gone silent,” with multiple dead prairie dogs or a sudden loss of activity, it could be a sign of plague.
What to Look For in Humans
Signs of plague infection can occur after a two- to six-day incubation period. Symptoms include:
- Fever
- Chills
- Generalized pain
- Diarrhea
- Shock
- Extreme physical weakness
- Bubonic plague: painful swelling under the arms and groin
- Septicemic plague: central nervous system signs, bloody urine and saliva, and red splotching of the skin
- Pulmonary plague: coughing, bloody mixture of saliva and mucus brought up by coughing, and difficulty breathing
Tularemia
Tularemia is a fatal disease caused by the bacterium Francisella tularensis. It infects beavers, other rodents, rabbits and hares — it can also infect humans and domestic animals. Infection is usually transmitted through ticks, biting flies and fleas, or by breathing in infectious droplets from soil or contaminated water.
Infections can be fatal if not detected and treated promptly. Contact your physician immediately if you feel ill or develop skin lesions following contact with wild animals, fleas, flies, other biting insects or ticks.
What to Look For in Animals
- Multiple sick or dead rabbits or rodents (including beavers)
- Pinpoint white spots throughout the liver and spleen of an animal — not to be confused with tapeworm tracks in the liver
What to Look For in Humans
Symptoms can include a sudden onset (one to ten days, average three days after exposure)
- High fever
- Shaking chills
- Weakness
- Fatigue
- Slow-healing ulcers (sores) at the site of an insect or tick bite
Highly Pathogenic Avian Influenza
Certain kinds of influenza viruses can cause a disease known as “avian influenza” in birds. Some species of ducks, shorebirds and other wild birds naturally carry the virus without getting sick — they have the infection but not the disease. But some of these viruses can cause disease in other species, including swans, turkeys, grouse, quail, diving ducks, gulls, geese, grebes, raptors, vultures, cranes and terns.
Each of the many kinds of avian influenza all fall into one of two categories: 1) low pathogenic (LPAI) types, which typically cause little or no signs of disease in domestic poultry and 2) highly pathogenic (HPAI) strains, which can cause severe disease and potentially high death rates in domestic poultry.
Although rare, some strains of HPAI can infect humans. Avoid handling sick or dead birds and keep your distance from wildlife. See the Center for Disease Control website for more information on protective actions for people.
What to Look For in Birds
- Swimming in circles
- Head tilting
- Lack of coordination
- Swollen head
- Diarrhea
- Moving slowly
- Ruffled feathers
- Respiratory signs
- Not eating
Canine Distemper
Canine distemper is a viral disease of wild and domestic carnivores. Coyotes, foxes, raccoons, skunks and black-footed ferrets are the most common animals to be infected. The virus does not survive long outside the body, so it spreads mainly through direct contact with an infected animal rather than through feces or the air. Canine distemper has a wide range of symptoms and, normally, is fatal. Because the symptoms are similar, sick animals should be tested for rabies.
Canine distemper can’t be transmitted to humans but can be transmitted to unvaccinated domestic dogs. Please defer to your veterinarian for proper vaccination protocols. Report any contact with wild animals to your local department of public health.
What to Look For
- Abnormal behavior
- Lack of coordination, seizures
- Weakness, slow-moving
- Crusting around eyes and nose
- Coughing
- Diarrhea
- Vomiting
- Thickened paw pads
Mange
Sarcoptic mange is an infestation of the skin by mites (Sarcoptes scabiei) that causes hair loss and severe skin irritation. Mange is highly contagious and can be transmitted by skin-to-skin contact or contact with infected material, such as bedding. Serious cases can cause blindness, hearing loss, difficulty eating and sometimes even death in animals such as coyotes, foxes, black bears, porcupines and fox squirrels.
Mange can be transmitted between wildlife, domestic animals and humans, although a severe infection typically only occurs when an animal contracts it from another of the same species. Pets can be protected from infection by preventing contact with wildlife and using mite-controlling products prescribed by a veterinarian.
What to Look For
- Hair loss, especially over the lower legs and tail (giving it a “rat-tail” appearance)
- Thick crusting or scaling of the skin
- Intense itching and scratching
- Thin, debilitated animals
Avian Botulism
Avian botulism is a toxic disease that causes large die-offs of waterfowl and other bird species. The disease is transmitted during summer months when birds feed in contaminated water. Avian botulism does not typically cause human disease. It’s rare for domestic dogs and cats to become infected, but cases have been reported.
What to Look For
- Large numbers of dead or sick waterfowl, especially mallards
- Birds that seem weak or unable to move
Report Signs of Sickness
If you or your pets are experiencing any of the symptoms listed above, especially after any contact with wildlife, please seek care from your doctor or veterinarian. Report your conditions or interactions to the proper agencies so they can better track potential outbreaks.
Contact Your Doctor
Contact your doctor immediately if you or your pet suffers a bite, scratch or other contact from a wild animal, or if you or your pet become ill or develop skin lesions following contact with wild animals, ticks or biting insects such as fleas.
Report Sick Wildlife
Any wild animal that appears sick or is acting strange or aggressive should be reported to the nearest CPW office and your local animal control agency.
Contact a CPW OfficeDiseases in Pets
Parasites and Tapeworms
Dogs and cats can become infected with tapeworms if they eat infected wildlife.
Tapeworms are common parasites of cottontail and jackrabbits. These types of tapeworms don’t pose a risk to human health — and should not be confused with diseases with some similar symptoms such as tularemia — but may cause intestinal infections if eaten by domestic dogs or cats. Taenia pisiformis is one of the most common.
What to Look For
- Fluid-filled cysts, each containing a floating white dot, on the belly or chest of a rabbit or hare
- Thick, white spots or lines at the surface of the liver of a rabbit or hare
Hydatid cysts, found on the lungs and liver of infected moose or elk, are large, fluid-filled cysts containing immature tapeworms. Moose and elk can become infected by eating wolf, domestic dog or coyote feces while grazing. Cysts in harvested elk and moose organs are not infectious to people but can infect domestic dogs, and the disease can spread to humans through pet waste. Consult your veterinarian for regular deworming of pets.
What to Look For
- Large, fluid-filled cysts that contain hundreds of tiny white grains — known as “hydatid sand” — in lungs or liver
- May be confused with common cysticercosis that does not affect people
The most common parasites encountered by big-game hunters are the tapeworms Taenia hydatigena and Taenia ovis krabbei: Both cause a disease in deer, elk, moose, bighorn sheep and pronghorn known as cysticercosis. These worms live in the intestines of wild carnivores such as coyotes, foxes, mountain lions and bobcats. When these carnivores defecate, tapeworm eggs get onto the ground and the grass; big-game animals then swallow the eggs as they graze, leading to infection. Cysticercosis does not pose a risk to human health, but may cause intestinal infections if eaten by domestic dogs or cats.
What to Look For
- Large (1-inch) fluid-filled cysts, each containing a floating white dot, in the belly or chest
- Small (1/4-inch) fluid-filled cysts, each containing a floating white dot, in the muscle tissue
Living with Wildlife
Prevent Disease
There are several steps you can take to help prevent the spread of disease. It is natural to want to help sick or injured wildlife, but it's not worth endangering yourself or your pets. Where possible, call your nearest Colorado Parks and Wildlife office for help.
Avoid Dead Animals
- -Do not consume birds or animals that are found dead.
- Do not handle or allow your pets near sick, injured or deceased wildlife.
- Lakes and ponds with large numbers of dead birds may have diseases present — it’s not recommended to swim in affected waters.
- When hunting, do not skin or consume sick or dead animals.
Handling Animals
- Avoid handling wildlife, but if contact is necessary always wear gloves and wash your hands.
- When field dressing carcasses, protect yourself from contact with tissues, fluids and parasites (i.e., ticks, fleas, etc.).
- Warn children to never handle an unfamiliar animal. If an animal lets you approach or handle it, there's something wrong with it.
Many animals will bite in self-defense if you attempt to handle them.
Pets
- Keep pets in yards, kennels or on a leash. Pets that are allowed to run loose are more likely to come in contact with infected animals, or disease-carrying pests that they can bring into your home.
- Do not allow free-roaming pets to sleep on your bed.
- Use flea, tick and mite preventatives on your pets.
- Pets should not eat or play with dead or decaying bird or animal bodies.
Disease in Domestic Animals and Cattle
See the Colorado Department of Agriculture's website for information.