Brucellosis Facts

Brucellosis is an important venereal disease in many species. Once someone has decided to breed their dog, it behooves them to know all about this disease, particularly since it can be transmitted to humans.

ALL DOGS TO BE BRED SHOULD HAVE A BRUCELLOSIS TEST. If you are planning to breed your dog, test your dog and insist that the owner of your dog’s mate produce results of a recent test for your inspection.

Which Type of Brucella: There are six species of Brucella and the dog is mostly concerned with Brucella canis; however, dogs can certainly become infected with Brucella abortus (from cattle), Brucella melitensis (from goats) and Brucella suis (from pigs) if they are allowed to drink contaminated milk or eat leftover birth membranes, contaminated meat, or aborted young. Luckily for humans, Brucella canis causes much less serious disease in humans than do the livestock The health department still considers any Brucella infection reportable.

How Dogs Get Infected? Dogs like to stick their noses in all sorts of nasty places. They also chew up all sorts of disgusting things. Brucellosis can be contracted sexually but it can also be contracted by inhalation (sniffing contaminated urine or fetal membranes), through the eyes, or orally (licking contaminated urine or urogenital secretions, or chewing up fetal membranes). Urine and saliva from an infected dog are not nearly as rife with organism as urogenital secretions; it is when breeding and/or whelping is in the picture that the transmission risk becomes very high. When a female dog aborts a pregnancy because of a Brucella infection, she continues to secrete fluids packed with Brucella bacteria for 4 to 6 weeks.

What Happens After Infection? The organism requires 3 weeks on the average to become evident in the bloodstream. After that they localize in the reproductive or urinary tract and either continuously or periodically seed the bloodstream from there. Lymph nodes can enlarge and possibly the spleen or liver can become inflamed, but generally the infected adult dog does not seem sick. Chronic disease from long term immune stimulation can result. This can include: Diskospondylitis (inflammation of a disc in the spine) Uveitis (deep eye inflammation) Multiple joint arthritis Glomerulonephritis(kidney inflammation and protein loss)

Most of the time, the only sign is aborted pregnancy between the 45th and 59th day of pregnancy (relatively late in the pregnancy). Classically, the aborted pups appear to have died at least several days prior to abortion as they do not look freshly dead. Abortion does not always appear in this most common form, though. Sometimes, the pregnancy is lost much earlier and is deemed to represent infertility. Sometimes puppies are still born. Sometimes they are born live and infected.

Testing Direct culture of the organism from a dead puppy, infected dog’s blood or from secretion is confirmatory but the organism is difficult to isolate in this way. This means we usually depend on immunologic tests. Which test is selected depends on what the test is being used for.

Screening Before Breeding: The RSAT (Rapid Slide Agglutination Test) is a screening test that can readily identify negative dogs. That is, if the test comes out negative, the dog can be considered negative. If the test comes out positive, further testing is needed. Up to 60% false positives occur. A test kit is available for use inside the veterinary hospital and some facilities can perform this test while you wait.

The IFA (Immunofluorescent Antibody) test is a similar screening test but it must be sent to the reference laboratory. The same guidelines apply: negative means negative, positive means do further tests.

Treatment First of all, the infected dog must be removed from the breeding program (spayed, neutered and in bad cases euthanized) and isolated from any animals to be used for breeding. The dog can remain as a pet but probably should not be sold due to potential health risks to potential buyers. For pet dogs, a course of antibiotics can be given but since this bacterium is so good at hiding inside the host’s cells, one can never assume it is ever truly gone. Some people keep their dogs on tetracycline for life. Dogs do recover from this infection without treatment but it can take up to 5 years. Naturally recovered dogs cannot be reinfected; antibiotic-treated dogs can be reinfected.

Keeping Brucella Out of the Kennel A new dog for a breeding kennel should be isolated for one month. Two Brucella tests one month apart should be adequate to confirm negativity (it takes about 3 weeks from infection for tests to turn positive). If an infection is detected in a kennel, the entire kennel population should be evaluated.