Zoonoses are diseases that can be transmitted from animals to people. The following guide details the occupational hazards associated with canines, and the precautions necessary for minimizing the risk of animal-to-human diseases.
Disease transmission from human to animal may also be a concern, particularly when working with potentially immunocompromised animals, such as in immunology or oncology experiments. Contacts are provided for further assistance.
When working with dogs, take the following protective measures:
- Always wear gloves and a laboratory coat, or other dedicated protective clothing, such as a scrub suit. In some cases, masks or protective eye wear is also indicated.
- While working in an animal use area, do not eat, drink, or apply cosmetics.
- After handling dogs, always wash your hands.
- Be aware that unfixed tissues, body fluids, and other materials derived from dogs also pose a risk.
Contact EH&S at (650) 723-0448 for any concerns or questions you have about working with dogs. Contact the Veterinary Service Center at (650) 723-3876 for help with training personnel.
Note that all personnel working with dogs are eligible to enroll in the Laboratory Animal Occupational Health Program (LAOHP). Contact EH&S at (650) 723-0448 for additional information.
Dogs used in research have been vaccinated against rabies. However, it may be prudent to also consider prophylactic immunization.
Bites and scratches may pose serious problems through trauma and/or bacterial infection. Dogs may also have eneteric bacteria (e.g. salmonella) in their feces, so cage washers and any personnel who clean bedding should always wash their hands with a disinfectant hand soap before leaving the facility.
Dogs, like most mammals, can shed fur, so anyone with allergies to fur, dander, or animal bedding should wear personal protective clothing to minimize discomfort. Dogs may also carry biting insects, such as fleas, so personal protective equipment may also be used.
The following describes some of the causative agents and potential illnesses associated with dogs, along with protective measures, signs of illness, and what to do if an exposure or injury occurs.
Brucella canis
What is Brucella canis?
This is the bacterium that causes canine brucellosis. One of several types of brucellosis, it is the least harmful to humans. The disease can result in reproductive failure of sexually mature dogs.
How is Brucella canis spread?
Human infection with Brucella canis occurs by direct contact with secretions (e.g. vaginal fluids, urine, and seminal fluids) from infected animals. The most commonly reported laboratory-associated bacterial infection, transmission can also occur from exposure to infectious aerosols.
Who is at risk for infection?
The overall risk of human infection is low, but veterinarians and researchers who work with dogs that may be infected should take precautions. Additionally, veterinarians and researchers who work with or have exposure to the Brucella canis vaccine can develop an infection.
Is Brucella canis infection serious?
Human infections with Brucella canis are relatively mild.
Clinically, infected dogs are rarely seriously ill. Obvious clinical signs usually involve reproductive disorders in sexually mature animals. Puppies are usually aborted, or die within the first few days after birth.
How can I protect myself?
Pet dogs should be neutered before treatment to decrease the risk of infecting humans. Although aerosol transmission is likely, survival of the Brucella organism in the environment is probably short-lived.
Proper disinfection with quaternary ammonium compounds or iodophors should be implemented to prevent the spread of infection. Infected animals should be handled with gloves and never bred, not even by artificial insemination. Dogs kept as pets should be neutered and should not be allowed in the kennel environment. Gloves, shoe covers, and long sleeved apparel should be worn at all times when working with dogs. Always wash hands after handling animals.
What are the signs of Brucella canis infection?
Human infections with Brucella canis are relatively mild. Symptoms may include fever, malaise, enlarged lymph nodes, and weight loss. Some infections may be asymptomatic.
What do I do if an exposure or injury occurs?
Exposure to aerosols, bites, or scratches involving animals, or injuries from objects contaminated with body fluids from animals, require immediate first aid and medical attention. Always notify your supervisor immediately.
Between 8:00 am and 5:00 pm., proceed to Stanford Occupational Health Clinic at 480 Oak Road, Room B15, 5-5308.
After 5:00 pm and before 8:00 am., call (650) 723-2670 or proceed to the Stanford Emergency Room, H126 (in the hospital, next to the cafeteria).
Campylobacteriosis
What is campylobacteriosis?
Commonly found in untreated water, and the intestines of poultry, cattle, swine, rodents, wild birds, and household pets (e.g. cats and dogs), campylobacteriosis is a bacterial illness caused by Campylobacter jejuni. C. jejuni is the leading cause of bacterial diarrhea in the United States.
How is campylobacteriosis spread?
Most commonly, people develop campylobacteriosis after consuming undercooked poultry, raw milk, or non-chlorinated water that has been contaminated. C. jejuni may also be transmitted through ingestion after petting infected cats and dogs, whose coats may contain infected fecal matter. In the event of inadequate hygiene, person-to-person transmission may also occur through human fecal matter.
Who is at risk for infection?
Although anyone can develop a C. jejuni infection, children under 5 years and young adults (15-29) are more frequently affected than other age groups. Persons who are immunocompromised (such as AIDS patients, or cancer patients on immunosuppressive therapy) are believed to be more susceptible to health complications following infection. The elderly may also be more susceptible.
Is campylobacteriosis infection serious?
Complications are relatively rare, but infections have been associated with reactive arthritis, hemolytic uremic syndrome, and septicemia.
How can I protect myself?
- Wear gloves, shoe covers, and long sleeved apparel at all times when working with animals.
- Thoroughly wash hands after handling animals.
- Sanitize lab and surgical areas after animal work.
- Use disposable supplies whenever possible.
What are the signs of campylobacteriosis?
Symptoms of campylobacteriosis include fever, headache, and muscle pain, followed by diarrhea, stomach pain, and nausea. Symptoms usually occur within 2 to 10 days of ingestion. It may take anywhere from a few days to a few weeks to recover.
What do I do if an exposure or injury occurs?
Exposure to aerosols, bites, or scratches involving animals, or injuries from objects contaminated with body fluids from animals, require immediate first aid and medical attention. Always notify your supervisor immediately.
Between 8:00 am and 5:00 pm., proceed to Stanford Occupational Health Clinic at 480 Oak Road, Room B15, 5-5308.
After 5:00 pm and before 8:00 am., call (650) 723-2670 or proceed to the Stanford Emergency Room, H126 (in the hospital, next to the cafeteria).
Rabies
What is rabies?
Rabies is a widespread infection of warm-blooded animals caused by a virus that attacks the nervous system. In North America, rabies occurs primarily in skunks, foxes, and coyotes. In some areas, these wild animals may infect domestic cats, dogs, and livestock. In the U.S., cats are more likely than dogs to be rabid. Bats can also transmit rabies.
As a general rule, rabies is rare in rodents (e.g. beavers, chipmunks, squirrels, rats, mice, muskrats, hamsters, gerbils, porcupines, and guinea pigs). Rabies is also rare in rabbits.
How is rabies spread?
The rabies virus enters the body through a cut or scratch, or through mucous membranes, such as the lining of the mouth and eyes. From there, it travels to the central nervous system (brain and spinal cord). Once the infection is established in the brain, the virus travels down the nerves from the brain and multiplies in many different organs.
The salivary glands are the most important organs in the spread of rabies from one animal to another. When an infected animal bites another animal, the rabies virus is transmitted in the infected animal’s saliva. Claw scratches from rabid animals are dangerous because animals usually lick their claws. Saliva applied to a mucous membrane, such as the lining of an eyelid, can also be dangerous.
Bat excreta contain enough rabies virus that people who enter bat-infested caves can catch rabies by breathing in aerosols.
Who is at risk for infection?
Anyone who comes into contact with possibly infected animals (especially wild animals) is at risk for infection.
Is rabies infection serious?
Once the symptoms of rabies develop, it is 100% fatal. Patients develop difficulty swallowing saliva (hence the term “foaming at the mouth”), and even the sight of water may terrify some (hydrophobia). Some patients become agitated and disoriented; others grow paralyzed. Patients either die during this stage of the illness, or go into a coma and die from further complications.
How can I protect myself?
Vaccinate animals against the virus. Rabies in humans can be prevented either by eliminating exposures to rabid animals or by providing exposed persons with prompt local treatment of wounds, combined with appropriate passive and active immunization. Veterinarians and researchers at risk of being bitten by wild animals (such as field researchers) should seek pre-exposure vaccination.
What are the signs of rabies infection?
The incubation period in humans ranges from five days to more than a year. Two months is the average incubation period.
Since the disease is fatal once symptoms develop, it is crucial to seek medical attention if you believe you have been exposed. After the incubation period, there is a period of vague symptoms lasting from two to 10 days. The patient may have a fever, headache, malaise (general sick feeling), decreased appetite, and vomiting. There may also be pain, itching, or numbness and tingling at the site of the wound. More serious symptoms develop after this stage.
What do I do if an exposure or injury occurs?
Exposure to aerosols, bites, or scratches involving animals, or injuries from objects contaminated with body fluids from animals, require immediate first aid and medical attention. Always notify your supervisor immediately.
Between 8:00 am and 5:00 pm., proceed to Stanford Occupational Health Clinic at 480 Oak Road, Room B15, 5-5308.
After 5:00 pm and before 8:00 am., call (650) 723-2670 or proceed to the Stanford Emergency Room, H126 (in the hospital, next to the cafeteria).
Bites or scratches involving dogs, or injuries from objects contaminated with body fluids from dogs, require immediate medical attention. In these cases, always notify your supervisor.
Between 8:00 am and 5:00 pm, Monday through Friday, contact the Stanford University Occupational Health Center (SUOHC) at (650) 725-5111 for immediate phone triage and to schedule an urgent drop-in appointment time.
For immediate, life-threatening injuries, or when SUOHC is closed, go directly to the Stanford University Medical Center Emergency Department.
