Brucellosis in Dogs
People think of Brucellosis as abortion, but we mostly see it as conception failure, stillborns, or weak puppies. There is no treatment for Brucella canis
, and it can be contagious to humans, creating the need to eliminate it from our breeding population! Once introduced, eliminating Brucellosis is difficult and costly. Testing any additions into our breeding kennel is necessary to prevent it.
WHAT IS IT?
Brucellosis is a tiny bacterium that causes reproductive disturbances and abortion. It is potentially contagious to humans, but this is rare. Brucellosis causes a recurrent fever in humans.
Often open females are the first indication of Brucellosis. If you see discharge from the vulva at 30 days, we rule out Brucellosis. Chronically-infected females will build enough immunity to have a normal litter – all including mom will be infected!
The Brucella organism is spread primarily at breeding and with vaginal discharge. However, the Brucella organism is also found in semen, urine, aborted material and placenta. Chronically-infected males or females will shed when stressed, spreading the disease to other kennel mates. Stressed animals have intermittent bacteremia and shedding in all body fluids, even when not pregnant.
ABORTION AND INFERTILITY
Abortion with Brucella canis
occurs at 45-59 days pregnant. A vaginal discharge of highly-contagious gray-green fluid will last 1-6 weeks. This is a major source of spreading the disease in the kennel! Other signs of B. canis
are conception failure, fetal death and subsequent birth of mummies and weak puppies. Puppies born to infected bitches are infected with this non-curable disease.
HOW IT LIVES
Brucella lives inside cells of the urogenital track of females, making it difficult to detect. In males it resides in the prostate, epididymis or both. At times, few organisms are circulating in the blood with chronically-infected females, and this causes difficulty in diagnosis on blood tests.
Card test is currently off the market, and we don't see the card test coming back. The card test gave many false positives (picking up related bacteria) and false negatives because of intermittent bacteria in the sample.
Vaginal swabs and serum can be cultured for Brucella. Cultures will not give false positives because once you grow it, you have the disease. It can have false negatives from having no organisms being shed in the sample, but fewer than the card test.
AGUR GEL IMMUNE DILUTION
This test is ran in the lab by putting your samples and negative samples in wells and having them diffused through gel with antibodies to Brucellosis. The antibodies bind to Brucella and under certain wavelengths of light, they will fluoresce. These are compared to the negative samples to be sure it is accurate. This test usually takes 2 weeks to get results and is very expensive to run. In the past, Agar Gel Tests were ran to confirm positive results as it is very accurate.
NEW PCR TEST
A new test run by Iowa State and Kansas State is the PCR, which detects DNA genetic material. PCR for Brucellosis can pick up as little as 10 bacteria in the blood, making it accurate at levels not seen in other tests. This test eliminates the false positives and negatives that plagued tests in the past. The accuracy of PCR gives us more comfort with testing, plus it is fast. We can usually get turnaround the same week, although they tell you 10-14 days. This test is less expensive and more accurate than culture; eventually states will replace its requirement for culture with PCR.
PREVENT BRUCELLA CANIS
Any additions to your kennel should be tested with the PCR test and isolated for 4 weeks. Artificial insemination (AI) can also help prevent the risk of transferring the disease (see below).
ADULT DOGS BROUGHT IN
An adult dog infected with Brucella canis
is rarely ill. They will trigger a positive test, but there have been cases where dogs were put on Tetracycline or another antibiotic for 3 weeks to get them to test negative and then sold. Antibiotic will eliminate bacteria from blood (not in the cells) and cause positive dogs to test negative for a short time --> you purchase --> later they re-activate and infect your kennel. That is why we do not like adult dog purchases – too much risk and you never sell your best dog!
If you add adult dogs, test twice 60 days apart with PCR to be sure you did not get a negative on antibiotic. If they have been tested, confirm what test they used, get a copy for your files and never trust a test from the seller – do your own, as the risk is too high.
Puppies are far less risk but still a risk. When brought in, you should PCR test them to be sure they are clean. One PCR test and puppy from a known source will make me comfortable with the addition to my kennel.
Breeding females coming into the kennel should be Brucellosis-negative on PCR within 30 days of the breeding and arrive with the test results – otherwise, don’t breed! It is always best to breed AI from your male with no contact with outside female to decrease risk. The risk has made most of us refuse breeding other people’s females, but if you insist on testing negative for Brucellosis and using AI, it can be done safely.
There is no treatment to eliminate Brucella canis
, and elimination is difficult once it is introduced to your kennel. The new PCR test for all new additions to your kennel will help you in maintaining a Brucellosis-free kennel!
If you need help, call us at 1-800-786-4751.
Don Bramlage, DVM, Director of Veterinary Services at Revival Animal Health
The materials, information and answers provided through this website are not intended to replace the medical advice or services of a qualified veterinarian or other pet health care professional. Consult your own veterinarian for answers to specific medical questions, including diagnosis, treatment, therapy or medical