What is canine brucellosis?
Canine brucellosis is an infectious disease caused by coccobacilli (bacteria) of the genus Brucella which causes pregnancy arrest in bitches and alterations in semen quality in male dogs.
The agent responsible for this contagious dog disease is Brucella canis, a gram-negative bacterium that more specifically contaminates the canine species. But, more rarely, dogs can also be infected with the bacteria responsible for porcine, ovine and bovine brucellosis.
How can a dog catch it?
Contamination occurs through the digestive tract, by inhalation (when smelling contaminated products/secretions) or through the genital mucous membranes.
Most often, therefore, dogs become contaminated by contact with infected bodily fluids, by licking or inhaling contaminated urine or genital secretions as well as sexually during mating.
Is brucellosis contagious to humans?
Yes! Brucellosis is a zoonosis, i.e. an animal disease transmissible to humans. Human beings can become contaminated through contact with infected animals, their genital secretions, when handling abortions, etc. In humans, the disease results in fever and night sweats, headaches, muscle aches/aches and great fatigue and can in particular progress to chronic osteo-articular pain.
What are the symptoms of brucellosis in dogs?
In male dogs, brucellosis most often goes unnoticed and causes no symptoms. But, it can nevertheless lead to an alteration of the quality of his semen and be the cause of infertility. Some infected dogs nevertheless develop epididymitis, an inflammation of a small duct located in the scrotum and whose role is to transport sperm from the testicle to the prostate. A condition that has become chronic can also cause testicular atrophy.
Infected bitches may abort at an advanced stage of gestation (usually after day 45th of gestation) or give birth to stillborn or weak puppies which may die a few days after birth. They also often present with persistent vaginal discharge. Sometimes abortions are earlier and can go unnoticed so that the female dog is thought to be sterile.
In case of chronic infection, the bacteria can infect:
- intervertebral discs and cause spinal pain (discospondylitis),
- the eyes by causing anterior uveitis,
- or even the brain and cause hind limb ataxia.
How is canine brucellosis diagnosed?
The infection is usually diagnosed by a blood test. Two serological tests are necessary to confirm the diagnosis.
The most commonly performed blood test is called the rapid slide or tube agglutination test. It can detect infections three to four weeks after contamination. Its disadvantage is that it has a high rate of false positives so that positive dogs must be tested again and then have their disease confirmed by other testing methods (blood cultures of bacteria, PCR tests, agar immunodiffusion )
What is the treatment for brucellosis?
We use antibiotics to control the infection. However, treatment failures are frequent and an infected dog remains a potential vector for the bacteria throughout its life, even if it has become seronegative again.
For these reasons, surgical sterilization of the infected dog is recommended in order to reduce the excretion of bacteria in the environment, and thus reduce the risk of contamination of other dogs or humans.