With the dawning of spring comes plans of breeding and thoughts of puppies. It is at this time that we should be extra vigilant of canine brucellosis. Often times you hear veterinarians talking about testing breeding dogs for brucellosis, but what is brucellosis and why should you be concerned about your dog’s health with it?
What is Brucella canis?
Brucella canis is a bacteria that can lead to infertility in the dog or the bitch and causes the clinical disease, brucellosis. It is not a typical bacteria that responds nicely to treatment with antibiotics however. In complex terms it is a non-motile, gram-negative coccobacillus. Generally the host range is limited to domestic and wild canids.
How can your dog get brucellosis?
Infected animals will start to shed Brucella canis through different bodily excretions. The most common are vaginal discharge, aborted materials and semen. Due to this, brucellosis is often thought of as a sexually transmitted disease of dogs. It is very important however, to realize that although the highest amount of bacteria is shed in genital secretions, that brucellosis can be transmitted through other secretions such as nasal and salivary sections along with milk and urine to a lesser extent. Taking this information into account, most dogs are at a real risk of meeting the disease. This means that the disease can be spread at dog shows, hunt tests, hunting where other wild canids live, doggy day care, and even veterinary clinics. It is important to understand that this is not just a sexually transmitted disease and that even if your dog is a “virgin” or is neutered/spayed they are at risk of acquiring the disease.
How prevalent is Brucellosis?
Due to testing and prevention of transmission there is not a high prevalence of Brucella canis in our well taken care of house pets. This disease is not to be taken lightly however, there was a kennel confirmed positive for the disease in fall of 2015 in Wisconsin. Disease outbreaks recently have been more associated with commercial breeding facilities and are easily spread when the dogs leave the facility.
Why is Brucellosis a big deal?
The reason that veterinarians stress Brucellosis testing is because of the seriousness of the disease and its ability to affect people. When a disease is able to be spread from animals to people it is considered zoonotic. Although there is a low risk of transmission to people there is still a risk. In Wisconsin Brucellosis is considered a reportable disease and therefore all positive animals need to be reported to the state veterinarian. People can contract the disease by ingestion or mucus membrane contact with infected material. Symptoms in people are wide ranged including recurrent fever, muscle aches, decreased appetite, fatigue, and other flu like symptoms. As the disease progresses it can lead to heart, lung, and/or bone disease. Due to a similar presentation as the common flu, Brucellosis is often overlooked at first.
What signs are seen in dogs?
Generally the signs seen in dogs are associated with reproduction or the reproductive organs. Brucellosis can cause infertility, abortion, persistent vaginal discharge. In male dogs it can cause orchitis (inflammation of the testicles), epididymitis (inflammation of the epididymus), scrotal dermatitis, oligozoospermia (decreased sperm count), and overall infertility. As stated earlier, spayed and neutered dogs are at risk of contracting Brucellosis as well and therefore will not show the reproductive signs. Other signs that can be seen in all dogs are uveitis (inflammation of part of the eye), meningitis, diskospndylitis (inflammation of spine), glomerulonephritis (inflammation of the kidneys), and dermatitis. Just as in people, these are not thought of as specific signs for this disease and therefore Brucellosis can be overlooked as a possible cause for disease until the disease becomes worse. It is important that we as veterinarians and dog lovers do not forget that Brucellosis is real and present and we should be testing for it.
How do we test for Brucellosis?
A true definitive diagnosis requires culture and growth of Brucella canis from lymph node aspirates or other infected tissues or blood. This is a very hard organism to grow however so one negative culture (the organism does not grow) does not rule out Brucellosis. A faster method of testing is serologic testing. This is done by drawing blood from test subject and spinning the sample to separate the serum from the rest of the blood contents. Serologic testing is considered diagnostic once significant antibody titres have developed which can take greater then 8 weeks after infection. This means that a serologic test can be negative at the time of testing and the dog is still infected. You can see that there is obvious challenges with diagnosing this disease and for this reason there is ofter several layers of testing that goes on if a patient is suspect of the disease.
What is the treatment of Brucellosis?
This is the hard part of the disease. Although Brucellosis is caused by a bacteria, antibiotics are not useful for successful long term treatment. Also due to the human risk of disease it is taken very seriously. Therefore that current treatment for this disease is euthanasia. All animals exposed should be tested and positive animals are euthanized.
Here at Veterinary Village we are able to do in house serologic testing. We treat a negative result as truly negative and if the test comes up positive then further testing is required and the sample is sent to Cornell. Due to the seriousness of this disease it is strongly recommended that all breeding animals are tested prior to all breedings taking place.