Zoonoses Associated with Wild Ungulates
This document provides information on various diseases that can be passed from deer, moose, elk, duikers, caribou and bighorn sheep to humans. Many times, these diseases do not make the animal appear sick but can cause serious illness in humans. Persons with specific medical conditions such as an immunodeficiency and pregnancy may be at higher risk of developing disease or complications from a zoonotic disease and should consult with their physician before working with wild ungulates. The zoonotic diseases associated with wild cervids and bighorn sheep include Q fever, chlamydiosis, leptospirosis, campylobacterosis, salmonellosis, cryptosporidiosis, pathogenic E. coli infection, yersiniosis, giardiasis, dermatophilosis, tularemia, and rabies. Additional information on zoonotic diseases can be found on the Center for Disease Control and Prevention Website, Healthy Pets, Healthy People.
Tuberculosis and brucellosis are potential zoonoses in deer, elk and caribou but due to a federal eradication program for Mycobacterium bovis (bovine tuberculosis), Brucella abortus, Brucella suis and Brucella melitensis in cattle and captive deer, these diseases are uncommon in the United States. Tuberculosis is present in certain populations of white-tail deer and elk in the North Central United States and brucellosis is present in elk and bison in the greater Yellowstone area of Montana, Wyoming and Idaho. Wild caribou have been reported to carry Brucella suis. Captive cervid populations are subject to state and federal tuberculosis and brucellosis control measures. Animals affected by Brucellosis usually do not present any signs of illness but are suspected of having the disease when reproductive problems are evidenced as infection in the reproductive organs, abortions and stillbirth, or weakened offspring. People can acquire brucellosis after direct contact with infected animals or animal tissues and fluids, such as blood. The bacteria can penetrate damaged skin and mucous membranes. Infected people typically have flu-like symptoms and the disease can affect the reproductive organs and cause miscarriages. Bovine tuberculosis, although much rarer in people than the disease caused by M. tuberculosis, is a concern as it can also cause severe illness and death. People can become infected with M. bovis via direct contact with animals and their products (i.e., meat, hides), or body fluids, such as blood, since the bacteria can penetrate abraded skin. Inhalation of this agent in contaminated air is also a possible way of contracting the disease. Signs of the illness in animals include weakness, loss of appetite and weight, fever, etc. Symptoms in people affected by bovine tuberculosis include fever and weight loss and can affect several organs depending on the route of infection. Chronic wasting disease is a prion disease in deer that causes spongiform encephalitis similar to mad cow disease in cattle. It is not present in the Pacific Northwest and it has not been shown to infect people.
Coxiella burnetti and Chlamydophila abortus are bacterial agents associated with abortion in pregnant sheep, goats and cattle. These agents may also be carried by deer, moose, wild sheep and elk and may or may not result in disease. There is an especially high concentration of these agents at the time that the animals give birth, so particular care needs to be used in handling newborn animals, placental tissues and birth fluids. These agents can be acquired by exposure to placental membranes and fetuses from infected animals and by aerosol. Chlamydophila infections in pregnant women are associated with infectious abortion or miscarriage. Persons who are pregnant, have valvular heart disease or other chronic disease conditions should consult their physician before working with pregnant or birthing cervids or sheep.
Leptospirosis causes reproductive failure, anemia, liver and kidney disease in ruminants and is typically shed in the urine of infected animals. People acquire the infection by ingestion and skin contact with contaminated urine, placenta, and fetal tissues. The organism can infect hosts through abraded skin. In people, the disease causes fever, headache, abdominal and muscle pain, vomiting, diarrhea, jaundice, and rash. In more severe cases, it can cause hemorrhagic pneumonia, liver and kidney failure and can lead to death. Salmonellosis, campylobacterosis, listeriosis, pathogenic E. coli infections, cryptosporidiosis and giardiasis are acquired by contact and accidental ingestion of fecal material from infected animals. Animals infected with these diseases typically have diarrhea, but some animals may show no symptoms of disease. Any animal with diarrhea should be suspect of having a zoonotic disease. Symptoms in people include abdominal pain, diarrhea, and fever. Yersiniosis is acquired through bites from infected fleas or from contact with body fluids from infected animals. Symptoms of yersiniosis in people can include high fever and chills, headache, malaise, and swollen lymph nodes.
Dermatophilosis (aka Lumpy Wool or Strawberry Footrot) is a bacterial disease that is more common in deer than other wildlife. The disease affects the skin and hair and typically presents entrapped hair in crusty scabs with pus that give the coat a characteristic “paintbrush” matted appearance. This bacterium is transmitted to people via direct contact with infected animals. People affected by dermatophilosis have blisters with pus in the skin of their hands and arms that can progress to ulcers and leave scars.
Tularemia is a bacterial infection that can be present in wild ungulates. Infected animals may appear lethargic, have fever, and can become stiff and die within hours or days from initial signs, but may shed bacteria before showing illness. Tularemia is transmitted to people through bites from infected ticks or deer flies, direct contact with or consumption of meat of infected animals, or via airborne transmission if feces, urine, or body fluids from infected animals are aerosolized. In humans, the disease initially presents as fever, chills, headache, muscle aches, swollen and painful lymph nodes and possibly a rash or ulcer in the area of a recent bite, among other symptoms but may progress to pneumonia.
Rabies is a fatal viral infection that can be transmitted by bites, scratches and mucus membrane exposure from an infected animal. Captive animals can be infected from contact with free-living wild animals such as bats, skunks, and raccoons. Infected animals often exhibit neurological symptoms and unusual behavior. There is an effective vaccine available for people and most domestic animals including dogs but there is no rabies vaccine for wildlife or wildlife/domestic hybrids. Animals with undiagnosed neurological disease should be treated with caution to avoid possible exposure to the virus. Rabies is rare in the Pacific Northwest but if a person is bitten or has salivary mucus membrane contact from a suspect animal, the animal should be tested for the rabies virus. If exposed, persons should seek post-exposure rabies prophylaxis from a medical professional immediately. Persons who routinely work in high risk activities should be vaccinated against rabies.
Individuals with exposure to animals and animal environments may develop allergic reactions to animal proteins (allergens). Approximately 20-30 percent of individuals working with laboratory animals will develop an allergic reaction to animal proteins and 5-10 percent of individuals will develop asthma. Personnel may be exposed to allergens through inhalation and contact with skin, eyes and mucous membranes. Animal allergens may be present in animal dander, hair, skin, urine, saliva, serum and any contaminated feed or bedding materials. Risk factors for developing an allergic reaction include history of previous allergies to animals. The signs and symptoms of an allergic reaction are nasal discharge and congestion, conjunctivitis, tearing and eye itching, skin redness, rash or hives and lower airway symptoms (coughing, wheezing and shortness of breath). Individuals with symptoms suggestive of an allergic reaction related to a workplace allergen should report their concerns to their supervisor and consult a physician.
Transmission of zoonotic diseases from animals is primarily by direct contact, contact with contaminated bedding or materials, oral ingestion or inhalation of aerosolized fluids. We can protect ourselves from most diseases by using the following procedures:
- Handle animals safely to avoid injury. Thoroughly wash any wounds and report injuries
- Do not eat, drink, apply cosmetics or use tobacco products while handling animals or in animal housing areas.
- Wear gloves when handling ill animals, animal tissues, body fluids and waste and wash hands after contact.
- Wear respiratory protection when appropriate.
- Wear dedicated protective clothing such as a coat or coveralls and closed-toed shoes, shoe-covers or boots when handling animals. Launder the soiled clothing separate from your personal clothes and preferably at the animal facility.
- Keep animal areas clean and disinfect equipment after using it on animals or in animal areas.
Most importantly, familiarize yourself about the animals that you will be working with and the potential zoonotic diseases associated with each species. If at any time, you suspect that you have acquired a zoonotic disease, inform your supervisor and seek medical care.
**Prepared by Office of the Campus Veterinarian and the Office of Research Assurances January 2021
- Centers for Disease Control and Prevention. Healthy Pets, Healthy People.(https://www.cdc.gov/healthypets/pets/wildlife.html)