Canine brucellosis is a bacterial disease that causes fertility problems in dogs, so unless you’ve had a dog that you’ve used for breeding, it’s not likely that you’ve had reason to worry about this condition. Still, it's a condition worth knowing about—especially when your newly adopted adult dog has an unknown history.
Brucellosis is a venereal disease of dogs, but it can be transmitted through any mucous membrane. While we typically associate the spread of this disease through sexual contact, ingestion and inhalation of the bacteria that causes brucellosis can also lead to disease. This means that contact with contaminated tissues, including urine and fetal membranes, can transmit the disease. And though less common, it can also be spread to growing fetuses and to newborn pups through nursing.
There are six species of the bacteria Brucella, but clinical signs of brucellosis in dogs are generally caused by Brucella canis. This doesn’t mean that dogs can’t be infected by other species, though, so care should be taken when dogs are exposed to infected livestock tissues, as well. Canine brucellosis can affect humans, though the disease is not nearly as serious as human brucellosis from livestock. Still, brucellosis in dogs is reportable. This means that if your dog has been diagnosed, your veterinarian is obligated to report the disease to the health department.
Usually, there are no clinical signs of brucellosis until breeding is attempted. Male dogs may have poor semen quality, leading to poor fertility. Affected females typically abort puppies between 45 and 60 days of gestation.
Obviously, spayed and neutered dogs won’t show reproductive symptoms, but brucellosis can also cause other medical problems, including diskospondylosis (inflammation of the vertebral discs), osteomyelitis, ocular conditions, and kidney disease.
Before purposely breeding a dog, whether male or female, he or she should be tested for brucellosis. If the test is positive, that particular dog should not be used for breeding. Tests include blood tests, semen analysis, and tissue cultures.
Treatment is difficult due to the nature of the bacteria, which hides inside of cells, making it harder to kill with antibiotics. Often, the bacteria persist despite long treatment periods, and relapse is common. Affected dogs should be spayed or neutered to prevent further transmission of disease.
Like I said, your average pet owner will likely never have to deal with brucellosis, but it is worth keeping in mind if you have farm dogs or if your dogs frequent farms where there is the potential (however slight) to be exposed to the livestock form of brucellosis. For breeders, always test new dogs before breeding and keep them isolated from the rest of the kennel until they get a clean bill of health!