How it spreads in dogs

Dogs can be infected by breeding with an infected dog, or through direct contact with infectious material including urine, feces, saliva, blood, reproductive fluids and tissues, milk or contaminated objects.

Infected pregnant dogs can also transmit the disease to puppies in utero, during, or after birth. Resulting puppies may be stillborn, weak and sick, or be infected but appear normal and develop clinical signs later.

Because infected dogs may not look sick, undetected spread can happen in breeding, rescue, boarding, or multi-dog household settings.

Common symptoms in dogs

• Reproductive related:
  • Female dogs: Infertility, vaginal discharge, abortions, stillbirths, sick puppies, or infected puppies that appear normal at birth
  • Male dogs: prostate and testicular infection which can lead to urination problems and swelling and pain of the scrotum
• Back pain, stiffness, or joint pain
• Swollen lymph nodes
• Fever
• Decreased energy or appetite
• Eye inflammation
• Diskospondylitis (inflammation of the discs in the spinal column) seen on x-ray, which can lead to neurological signs
• Some dogs have no obvious clinical signs

Prevention & safety

There is no vaccine for B. canis, so prevention focuses on testing and careful management of positive dogs. Work with your veterinarian on the best testing and management options for your dog.

• Talk with your veterinarian about testing before breeding or after known exposure or reproductive problems. Testing is also important for internationally rescued or imported dogs from high-risk areas such as Mexico, Central America, South America, Africa, Asia, or southern U.S. states, as well as dogs from kennels or breeding facilities.
• If you're breeding dogs, regularly test all dogs and always test new dogs before breeding.
• If your dog is positive:
  • Humane euthanasia is strongly recommended as there is no proven cure for brucellosis in dogs. Relapses are common and periodic bacterial shedding occurs despite long-term antibiotic therapy. Lifelong isolation, ongoing testing and treatment, and possible chronic pain can significantly affect a dog's quality of life. Infected dogs also pose a lifelong health risk to people.
  • If euthanasia is not pursued, the dog must be spayed or neutered and isolated for life. This means the infected dog must be kept away from other dogs and people, especially those at higher risk for severe disease, including young children, older adults, pregnant people, and people who are immunocompromised.
  • Use gloves when cleaning and disinfecting surfaces, bedding, bowls, and other items contaminated by urine, feces, saliva, blood or other body fluids of an infected dog.

Human health risk

This infection is zoonotic, meaning it can spread from dogs to people.

People are most likely to be exposed when handling birthing materials, urine, blood, or other secretions from an infected dog.

Tell your physician about exposure to an infected dog if you become ill.

Guidance for Veterinarians

Clinical Suspicion

• Always document a thorough, lifetime travel history in any new dog patient or when a dog presents for new illness. Dogs infected with canis may have no clinical signs for prolonged periods, so it is important to inquire about all travel and origins, even if there has been no travel for a long time.
• Maintain an index of suspicion for canis. Consider B. canis for dogs (especially young dogs) presenting with suggestive clinical signs—particularly non-specific pain, lameness, joint pain, back pain, or diskospondylitis. Investigate the dog’s origin and acquisition history.
• In sexually intact or breeding dogs, prioritize canis in the differentials when there is a history of reproductive failure, abortion, infertility, or international importation.
• Report suspect or confirmed cases to LA County Veterinary Public Health (how to report).

Diagnostic Testing

• If B. canis is suspected, use appropriate diagnostic testing and interpret results in clinical context. If back pain is noted, consider spinal radiographs.
• Test dogs at least 12 weeks after their last potential exposure and at 6 months of age or older to reduce the likelihood of false negative results.
• Point-of-care and in-house testing are not recommended.
• Serologic screening tests: Rapid slide agglutination test (RSAT) and/or tube agglutination test (TAT). A combination of serologic screening tests improves diagnostic accuracy, as false negatives and false positives can occur.
• Dogs with positive serologic screening tests should undergo confirmation testing with an agar gel immunodiffusion (AGID) and blood culture or PCR. Because intermittent bacteremia occurs, blood culture may yield false negative results and repeat testing may be needed.
• Consult your commercial veterinary diagnostic laboratory regarding available tests. canis testing is also offered through multiple veterinary diagnostic laboratories associated with veterinary colleges.

Owner Education

• Educate Clients: Owners of dogs diagnosed with canine brucellosis should be educated on the disease, risk to other dogs and humans, and that the disease is considered lifelong with no reliable cure. Veterinarians should discuss treatment options including humane euthanasia which is strongly recommended, quality of life, and financial commitment for lifelong care and monitoring.
• Provide guidance on cleaning and disinfection to help reduce the risk of spread in the home.
• Work proactively with rescue groups, breeders, and importers to screen higher-risk dogs before transport, placement, or breeding. Discuss the potential for liability and reputational harm if B. canis enters the consumer market through their organization.

Practice Safety

• Use advance notice and intake precautions for suspect or confirmed cases. If possible, have clients alert the clinic before arrival and move the dog directly into an exam room, isolation area, or separate entrance to avoid contact with other animals.
• Use appropriate PPE when handling suspect or confirmed dogs, especially during higher-risk activities such as specimen collection, surgery, cleaning contaminated spaces, or contact with reproductive tissues or other body fluids. Use gloves, a disposable gown, eye protection, and an N95 respirator.
• Limit exposure to body fluids and contaminated materials. Avoid direct contact with urine, blood, reproductive fluids, wound drainage, and other potentially infectious materials, and keep exposed items and equipment separated until they can be cleaned and disinfected.
• Clean first, then disinfect thoroughly. Remove organic material before applying disinfectant, and follow product instructions closely, including required wet contact time.
• Alert the laboratory if brucellosis is suspected when submitting specimens so laboratory staff can use appropriate safety precautions.
• Respond promptly to staff exposures. If there is a splash, needlestick, or other suspected exposure, wash the area immediately and seek medical evaluation.

Veterinarian Guidance (PDF)

What breeders and rescue groups should know

• Always test dogs before breeding, transport, or placement.
• Screen new arrivals before mixing them with resident dogs. This will prevent your resident dogs from contracting brucellosis from new dogs.
• Do not breed dogs known or suspected to be infected.
• Develop a plan with your veterinarian for testing, isolation, cleaning, and communication if a dog tests positive.
• Alert adopters, fosters, handlers, and staff when there has been exposure and provide clear instructions about infection control and follow-up.
• Use USDA breeding-facility guidance to strengthen prevention and control practices in kennels and multi-dog settings.

Rescue Guidance (PDF)