By Dr. Becker
Brucellosis is a venereal disease caused by bacteria that invade the reproductive organs. It occurs in a variety of different animals through infection with several species of Brucella bacteria. In dogs, the bacterial culprit is usually Brucella canis (B. canis). After exposure, it takes the bacteria about three weeks to show up in the bloodstream, and then it sets up shop in the reproductive or urinary tract, and also continues to feed into the bloodstream.
If you are thinking about breeding your dog, it's important to be aware of this disease. Have your pet tested for Brucellosis, and insist the owner of your dog's potential mate do the same.
Symptoms of Brucellosis
Most adult dogs with brucellosis don't appear sick initially. Others develop symptoms like enlarged lymph nodes and/or inflammation of the spleen or liver. Left untreated, chronic immune stimulation by the Brucella bacteria can result in inflammation of the discs of the spine (a condition known as discospondylitis), uveitis (deep eye inflammation), glomerulonephritis (inflammation of the kidneys that results in protein loss), and multiple joint arthritis (polyarthritis).
However, most of the time, the only sign of a brucellosis infection in female dogs is an aborted pregnancy that occurs late term. Less common variations are a pregnancy that is lost early term rather than late, stillborn puppies, or the birth of live puppies that are infected. In male dogs, there can be swollen scrotal sacs that signal infection, shrinkage of the testicles, and/or infertility.
How Transmission Occurs
Brucellosis affects both male and female dogs and is passed from dog to dog in bodily fluids. The main route of transmission is through sexual activity. But the infection can also be transmitted through inhalation of contaminated urine or fetal membranes, through the eyes or the oral cavity, or ingestion of contaminated fluids such as urine or vaginal discharge. Airborne transmission is very rare, but has been reported.
Brucellosis spreads fastest among dogs living in close quarters, especially during breeding, whelping, or when a female dog aborts a pregnancy due to a Brucella infection. In the latter situation, the female will continue to secrete contaminated fluids for four to six weeks, making every dog that comes in contact with her susceptible to infection.
Brucella bacteria can survive in the environment for a long time. In moist, cool, dark conditions, it can survive for months. It's very important to note that brucellosis is a zoonotic condition, which means it can be transmitted to humans, though the chances of infection are quite low.
In humans, infection can occur when a person comes into contact with an animal or animal product infected with the Brucella bacteria. There are many different strains of Brucella bacteria, but people tend to encounter the strain dogs carry when a positive dog whelps, or gives birth. Humans assisting in the delivery of pups have the greatest risk of infection potential. If a person (usually immunosuppressed) contacts the bacteria present in the dog’s reproductive tract through a cut, wound or oral/nasal contact, it’s possible for a person to acquire the infection as well.
Diagnosing a Brucella Infection
The most common method for diagnosing brucellosis is a test called the rapid slide agglutination test. If your dog's results are negative for this test, he or she does not have brucellosis. The drawback to this particular test is that while it's very sensitive and can detect small amounts of bacteria, it can't distinguish between closely related bacteria types. This results in a lot of false positives for brucellosis.
If your dog tests positive on a rapid slide agglutination test, further testing should be done to confirm a diagnosis of brucellosis.
A version of the agar-gel immunodiffusion test is considered the most accurate test for the disease.
Unfortunately, there's no dependable treatment available for brucellosis. Long-term antibiotic therapy is sometimes used. But in most cases, the drug only reduces the level of bacteria in the bloodstream. It doesn't successfully destroy all the Brucella bacteria present in the dog's body. Dogs diagnosed with Brucella are considered positive for the disease for the rest of their lives.
Interestingly, dogs have been known to recover from brucellosis naturally. However, it can take as long as five years for their immune system to clear the infection completely. Dogs who naturally recover from this disease can't be re-infected, whereas dogs treated with antibiotics can acquire the infection again.
Animals that have been infected with Brucella should never be bred. Infected dogs should be separated to prevent transmission to healthy animals. Because brucellosis is zoonotic, people with weakened immune systems or those who have had autoimmune disorders should not be exposed to an animal that is positive for Brucella.
Holistic veterinarians often use immune supportive herbs, nutraceuticals, and homeopathics to help bolster a dog's positive immune system response. And of course there is always a focus on excellent nutrition, including whole fresh foods that nourish the immune system.