This week I thought we could brush up on Brucella canis; an uncommon (in the northern US and Canada) cause of discospondylitis in dogs and a zoonotic disease of importance for humans. Why should we talk about this? Because I was contacted by a Wisconsin vet to help manage this case and I thought we could all benefit from this endeavor.
What is Brucella canis?
Brucella is an intracellular bacteria that is known to be a cause of abortions and still birth in dogs. Dogs are the known reservoir for this bacterium however other Brucella spp. can be transmitted to dogs on rare occasion.
What signs does it cause?
Brucella canis is known to cause abortion and stillbirth in dogs but it's lesser known signs include discospondylitis, uveitis and fatigue/fever. Have I mentioned this is zoonotic? Wear gloves when handling the dogs, and any excrement. Avoid contact if pregnant.
When should I test a dog for Brucella canis?
Any dog with a history of chronic back pain that is diagnosed with discospondylitis should be tested for Brucella canis. The original case I was involved with had a several year history of "not wanting to be petted on the lumbar spine" that progressed to overt signs of pain over a few months. Another case was imported from Canada (not exactly a hotbed of B. canis activity!) with signs of back pain over several months duration and the most recent case I am working with the dog has a several month history of back pain, as well.
How do you treat Brucella canis in dogs?
Management is NOT recommended by experts and State Veterinarians due to the risk to human health and the poor likelihood of actual cure. No universally accepted treatment protocol is available however several choices in published literature include tetracycline-based antibiotic, aminoglycosides, enrofloxacin or rifampin. Some protocols recommend 2 or more drugs in combination, others have solo management. Repeated screening every 2-6 months, regardless of signs, is recommended. If treatment is going to be stopped, two sequential negative tests are recommended before stopping antibiotics. This is likely to be 8+ months after initiation of treatment...if ever. However, screening should continue life long to catch subclinical relapses. Again, euthanasia is recommended by the veterinary community.
What do you do if you have a suspected or confirmed B. canis infection in a dog?
If you live in in the USA, call your State Vet. This is a reportable disease and must be reported! Furthermore, the state vet can provide additional guidance on treatment, testing and culling.
Wisconsin State Vet contact information:
Phone: (608) 224-4872, Monday-Friday, 7:45 a.m.-4:30 p.m.
Evenings & weekends: (800) 943-0003, after-hours. Tell the duty officer you are reporting a potential animal disease.
If you live outside of the USA - contact your local veterinarian for further guidance.
If you wish to read more about B. canis the most recent article from North America that I found is: Cosford KL. Brucella canis: An update on research and clinical management. Can Vet J 2018: 59:74-81.