Living with Wildlife
Wildlife Diseases
If wildlife acts aggressively, it may be an indication that it is sick or injured. 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 by touching or being bitten by a sick wild animal.
Diseases in Humans and Pets
Rabies
Rabies is a virus that attacks the central nervous system of mammals. The virus is shed in the saliva of an infected animal and is transmitted through introduction of saliva to open wounds, cuts or mucous membranes, like eyes, nose and mouth (mainly through bites) . Although rabies has been detected in Colorado, cases are relatively rare. Bats and skunks are the main sources of rabies in Colorado, it is less common in other animals. Rabies can be transmitted to humans and domestic pets. If you or your pet suffers a bite, scratch, or other contact from a wild animal, contact your physician immediately for advice regarding the possible need for rabies post-exposure vaccination. Pets should be vaccinated against rabies. If an animal, including a human, is exposed to rabies and does not treat it, the infection will be fatal.
What to Look For
- Aggression, no fear of humans, or passive if paralysis has set in
- Bats or skunks out during the day
- 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 through a type of flea that carries the disease, by contact with contaminated fluids or tissue, or by breathing in infectious droplets. These fleas are fairly species specific, meaning they will tend to stay close to their "host species," (prairie dogs, ground squirrels, chipmunks, mice, rabbits and other small mammals, wild cats). Plague can infect humans and domestic animals, and infections can be fatal if not detected and treated promptly. Most human cases result from flea bites. 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
- Multiple dead prairie dogs or loss of prairie dog activity in a colony
- Swollen lymph nodes on pet cats
- Fever or other nonspecific signs of disease in pet dogs or other species with access to prairie dog habitat
What to Look For in Humans
Signs of plague infection can occur after a 2-6 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 sputum, and difficulty breathing
Tularemia
Tularemia is a fatal bacterial disease (Francisella tularensis bacterium) of rabbits/hares, beavers and other rodents that can spread to humans and other species. Infection is usually transmitted through ticks, biting flies, fleas (or other blood-sucking arthropods) or by breathing in infectious droplets from soil or contaminated water. Infections can be fatal in humans and domestic animals if not detected and treated promptly. Contact your physician immediately if you feel ill or develop skin lesions following contact with wild animals, ticks, fleas, or other biting insects.
What to Look For
- Multiple sick or dead rabbits or rodents (including beavers)
- Pinpoint white spots throughout the liver and spleen, not to be confused with tapeworm tracks in the liver
What to Look For in Humans
Symptoms can include a sudden onset (1-10 days, average 3 days after exposure)
- High fever
- Shaking chills
- Weakness
- Fatigue
- Often slow healing ulcers (sores) form at the site of the arthropod bite
Tetanus
Tetanus, (commonly called lockjaw), is caused by Clostridium tetani bacterium. Tetanus is not transmitted by humans, but is contracted through a deep cut or wound that becomes contaminated with tetanus bacteria. Prairie dogs carry the bacteria in their mouths and can transmit the bacteria through a bite. Consult your medical doctor about vaccination protection against tetanus which can be prevented with a safe and effective vaccine.
What to Look For in Humans
Symptoms usually begin 8 days after the infection, but may range in onset from 3 days to 3 weeks.
- Headache
- Muscular stiffness in the jaw and neck
- Difficulty swallowing
- Rigidity of abdominal muscles
- Sweating
- Fever
- Severe muscle spasms follow, including "locking" of the jaw so the patient cannot open their mouth or swallow, and may even lead to death by suffocation
Highly Pathogenic Avian Influenza
Avian influenza is an infectious disease of birds caused by a group of influenza viruses. These viruses naturally circulate in wild birds, such as waterfowl and shorebirds, which can carry the virus without showing any signs of disease. Strains can occasionally cause disease in some wildlife species including swans, turkey, grouse, quail, diving ducks, gulls, geese, grebes, raptors, vultures, cranes and terns. The many strains of avian influenza are classified into two categories: low pathogenic (LPAI) strains which typically cause little or no clinical signs in domestic poultry, and highly pathogenic (HPAI) strains which can cause severe disease and potentially high mortality in domestic poultry.
Although rare, some strains can infect humans. The main protection is to 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
- Swimming in circles
- Head tilt
- Lack of coordination
- Swelling of the head
- Diarrhea
- Moving slowly
- Ruffled feathers
- Respiratory signs
- Not eating
Canine Distemper
Canine distemper is a viral disease of wild and domestic carnivores with a wide range of symptoms. Animals usually infected include raccoons, coyotes, skunks, foxes and black-footed ferrets. Spread of the virus is mostly by direct contact with infected animals as the virus does not survive long outside the body. Sick animals usually do not survive. Because distemper cannot be clearly distinguished from rabies without testing of the brain, sick animals should be tested for rabies. Canine distemper cannot be transmitted to humans, but may be transmitted to unvaccinated domestic dogs. Please refer to your veterinarian for proper vaccination protocols for your pets. Please report any contact with wild animals to your local department of public health.
What to Look For
- Abnormal behavior
- Incoordination, 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), which causes hair loss and severe irritation of the skin. 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 to the animal (coyotes, foxes, black bears, procupines, fox squirrels). Mange can be transmitted between wildlife, domestic animals, and humans, although severe infections typically only occur when transmission is between animals 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 (rat-tail)
- 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 Colorado 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. Humans usually become infected with botulism when they eat improperly stored food items. It is rare for domestic dogs and cats to become infected with avian botulism, 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 to better track any 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 feel ill or develop skin lesions, or your pet becomes sick, following contact with wild animals, ticks, fleas, or other biting insects.
Report Sick Wildlife
Any wild animal that appears to be sick or that is acting strangely or aggressively should be reported to the nearest Colorado Parks and Wildlife office and your local animal control agency.
Contact a CPW OfficeDiseases in Pets
Parasites and Tapeworms
There are several tapeworms that can spread to dogs and cats if they eat infected wildlife.
Tapeworms are common parasites of cottontail and jackrabbits that do not pose a risk to human health and should not be confused with other diseases such as tularemia. Tapeworms may cause intestinal infections if eaten by domestic dogs or cats. The most common parasite encountered by rabbit hunters in Colorado is the tapeworm Taenia Pisiformis that causes small fluid-filled cysts, each containing a floating white dot.
What to Look For
- Fluid-filled cysts, each containing a floating white dot, in 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 are large, fluid-filled cysts containing immature tapeworms in moose and elk, that were consumed by eating canid (wolves, domestic dogs, and coyotes) feces while grazing. Cysts in harvested elk and moose are not infectious to people but can infect domestic dogs. 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 “hydatid sand” in lungs or liver
- May be confused with common cysticercosis that does not affect people
- Hunters may recognize these hydatid cysts as containing hundreds of tiny white grains, also called “hydatid sand”.
Cysticercosis is common in most big game species in Colorado, including deer, elk, moose, bighorn sheep, and pronghorn. The most common parasites encountered by big game hunters are the tapeworms Taenia hydatigena and Taenia ovis krabbei. These worms live in the intestines of wild carnivores such as coyotes, foxes, mountain lions, and bobcats. Tapeworms spread when feces of these infected carnivores contain tapeworm eggs that are deposited on the ground and are eaten by grazing animals such as deer. 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 (¼ 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 other diseases present and it is not recommended to swim in affected waters.
- When hunting, do not skin or consume animals that you observe to be sick or dead.
Handling Animals
- Avoid handling wildlife, but if contact is necessary always wear gloves and wash hands.
- When field dressing carcasses, protect yourself from contact with tissues, fluids, and parasites (i.e., ticks, fleas).
- Warn children to never handle an unfamiliar animal. If an animal lets you approach or handle it, there's something wrong with the animal. Many animals may also bite in self-defense.
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 and bring them into homes.
- Do not allow free roaming pets to sleep on your bed.
- Use flea, tick and mite preventatives for your pets.
- Pets should not eat or play with dead or decaying bird or animal bodies.
Disease in Domestic Animals and Cattle
Pigeon Paramyxovirus
Pigeon paramyxovirus causes disease in pigeons and doves, and is responsible for die-offs of Eurasian collared doves in Colorado. The disease is spread through direct contact between birds. Outside the United States, some strains of the virus have infected birds other than doves and pigeons, including unvaccinated chickens. Although the disease has not been reported to infect humans, other avian paramyxoviruses can cause mild pinkeye in humans that have directly handled infected birds. Avian paramyxoviruses are not known to cause disease in dogs and cats.
What to Look For
- Die-offs of doves, with 3 or more birds found dead in a small area
- Sick birds that do not fly away when approached
Hemorrhagic Disease
Hemorrhagic disease is a fatal viral disease in white-tailed deer, and a sometimes fatal, but less severe disease in other species (elk, bighorn sheep, pronghorn, bison). Hemorrhagic disease is caused by two closely related viruses, epizootic hemorrhagic disease virus and bluetongue virus. The disease is transmitted by biting midges, usually in the late summer and early fall. Neither virus is transmissible to humans. Both viruses can be transmitted to cattle, but disease is typically mild.
What to Look For
- Multiple dead white-tailed deer, especially near water
- Dead animals during the fall season
- Edema (fluid) under the skin of harvested animals
- Cracked and sloughing hooves
- Abnormal antlers with retained velvet and are covered by bumpy growths
Sinus Tumors
Bighorn sheep sinus tumors are an infectious disease that causes thickening of the sinus lining or solid masses in the upper respiratory sinuses of rocky mountain bighorn sheep, desert bighorn sheep, california bighorn sheep and mountain goats. The cause of bighorn sheep sinus tumors remains unknown. Sinus tumors can be transmitted to domestic sheep.
What to Look For
- Thickened lining of the sinuses of the skull and horns
- Solid masses filling the sinus cavities
- Masses may be soft and gelatinous, hard and bony, or both.
- Masses invade bone and may cause horn or facial abnormalities.
- Thick nasal exudates, especially with concurrent bacterial infections
Hemorrhagic disease
Hemorrhagic disease is caused by bluetongue virus in sheep. The disease is transmitted by biting midges, usually in the late summer and early fall. The virus is not transmissible to humans. The bluetongue virus causes significant disease in domestic sheep, which are usually vaccinated against this virus.
What to Look For
- Multiple dead white-tailed deer, especially near water
- Dead animals during the fall season
- Edema (fluid) under the skin of harvested animals
- Cracked and sloughing hooves
- Abnormal antlers with retained velvet and are covered by bumpy growths
Rabbit Papillomas
Rabbit papillomas are growths on the skin caused by a virus. The virus is spread through direct contact and possibly through biting insect vectors such as ticks. Although there is no risk for transmission of this virus to humans or most domestic animals, there is a risk of transmission to domestic rabbits, especially if rabbits are housed outdoors where they may contact wild rabbits or biting insects. In domestic rabbits, the disease is more severe than in wild rabbits and should be treated by a veterinarian. Colorado Parks and Wildlife does not recommend euthanizing rabbits with papillomas unless they are interfering with the rabbit’s ability to eat and drink.
What to Look For
- Black nodules on the skin, usually the head
- Growths can sometimes become elongated, taking on a horn-like appearance
Rabbit Hemorrhagic Disease
Rabbit hemorrhagic disease is a highly contagious viral disease of domestic and wild rabbits (cottontail, jackrabbit, snowshoe hare or pika). The virus can be transmitted through contact with an infected rabbit, with body fluids or feces from an infected rabbit, or with a contaminated environment. The virus is very hardy and can survive on clothing, plant material, or other items that may be accidentally moved from an infected area. This disease cannot spread to people or domestic animals, but is a serious disease of domestic rabbits. Rabbit owners should exercise extreme caution to avoid accidental exposure. Domestic rabbits should not be housed outdoors in areas where rabbit hemorrhagic disease has been detected in wild rabbits.
What to Look For
- Multiple sick or dead rabbits/hares
- Affected animals may have blood staining the nose and mouth.