Brucella Canis
What is Brucella canis? Brucella canis is a species of bacteria that primarily infects dogs. It causes canine brucellosis, a contagious disease that can affect reproduction, cause systemic illness and less commonly spread to people (zoonosis). The bacterium is intracellular, meaning it lives inside host cells, which can make infection persistent and testing/treatment challenging.
How it spreads
Direct contact with infected fluids or tissues: urine, blood, saliva, aborted foetal tissues, placentas and vaginal discharges.
Mating: venereal transmission during breeding is a common route.
Indirect contact: contaminated equipment, bedding or surfaces can transmit the organism.
In utero transmission and from milk to puppies are possible.
Human infection is rare but can occur after close contact with infected dogs or contaminated materials.
Common signs in dogs
Reproductive problems: infertility, abortion (commonly in mid-to-late pregnancy), stillbirths, weak puppies.
Testicular swelling and pain in male dogs.
Lethargy, fever, reduced appetite, weight loss.
Lymph node enlargement.
Eye inflammation (uveitis)
Some infected dogs may show no signs (subclinical carriers).
Diagnosis
PCR testing can detect bacterial DNA and is useful in certain samples. Taking a blood sample and sending it to a lab.
Multiple tests and sample types over time may be needed because bacteremia can be intermittent.
Treatment and prognosis
Treatment usually involves prolonged courses of antibiotics (commonly doxycycline combined with an aminoglycoside such as gentamicin). Success varies and relapse is common.
Complete elimination of the organism can be difficult; many infected dogs remain carriers despite treatment.
In breeding animals, eradication from a kennel is difficult without strict testing, isolation, and removal of positives.
Euthanasia is sometimes recommended in breeding kennels or for chronic, untreatable cases to prevent spread.
Prevention and control
Test dogs before breeding, purchase or importation; quarantine and test new arrivals.
Use strict hygiene when handling pregnant bitches, whelping areas, aborted material and afterbirth. Dispose of foetal/placental tissues safely and disinfect contaminated areas.
Prevent contact between mating animals unless both test negative.
There is no widely used vaccine for B. canis in dogs in the UK.
Risks to people
Human infection is rare but possible, particularly for people with close contact to infected dogs (breeders, veterinarians, kennel staff).
In people, Brucella infections can cause fever, fatigue, sweats, joint and muscle pain and may become chronic if not treated.
Standard precautions (gloves, good hand hygiene, avoiding contact with birth tissues and discharges) reduce risk. Clinicians should be informed if human brucellosis is suspected.
Reporting and seeking help
If you suspect your dog has brucellosis, contact your veterinary surgeon promptly for testing and advice.
Inform your vet if your dog is intended for breeding, has recently aborted, or has been in contact with dogs from unknown or high-risk sources.
Reported cases may be subject to specific local or national guidance; follow veterinary public health advice for biosecurity and human health concerns.
Key takeaways
Brucella canis causes canine brucellosis, mainly affecting reproduction and occasionally causing systemic disease.
It spreads through infected bodily fluids and mating; humans can become infected but this is uncommon.
Diagnosis requires appropriate testing; treatment can be prolonged and may not eliminate the organism.
Prevention relies on testing, careful biosecurity and responsible breeding practices.
For specific case advice or testing, contact us.