Brucellosis is a bacterial infection which affects the reproductive organs that spreads from animals to people. The disease is spread by body fluids, with the main route of transmission being by sexual means. In addition to sexual means the disease can be transmitted during breeding. Most common dog to dog transmission is by nose and mouth contact with vaginal discharge of an infected female while inheat, ingesting contaminated fluids such as vaginal discharge or urine, abortion, and whelping. It is also commonly transmitted through semen and can be spread by infected urine for several years in chronically infected male cases, even after castration (removal of testicles). Puppies can become infected from their mother during pregnancy by way of the placenta. Animals and humans can also get infected by a placenta of infected animal, meat, unpasteurized milk, cheese and other dairy products. Airborne transmission is very rare but has been reported. The disease spreads quickly among dogs that are kept in closely confined areas especially during breeding times and when abortions occur. The most common way humans are infected include inhaling particles of, or direct contact, with canine abortion products (fetus, birthing fluid, placenta) or infected vaginal discharge via mucous membranes (mouth, nose, or eyes) or abraded skin. Infection can also occur after ingestion, either by contaminated hands or by allowing an infected dog to lick around the face and mouth area. Human infection associated with infected urine and feces is unknown, but thought to be a possibility. The Brucellacanis bacteria can live in areas with high humidity and low temperatures with no sunlight for long periods of time. Therefore, it can be transmitted by contact and/or inhalation of dust and dirt. It has also been shown to live in water, aborted fetuses, feces, equipment and clothing for several months.
Causes of Brucellosis
The causative agent for brucellosis is the bacteria Brucella canis. It is a gram-negative, rod shaped bacteria that resides inside the host’s cells. It is because of this intracellular characteristic that brucellosis is difficult to treat. Brucella canis is also a concern because it is a zoonotic disease, meaning it can be transmitted to humans.
Prevention of Brucellosis
Brucellosis is easy to prevent in dogs. There is no vaccine to prevent brucellosis, but there are steps you can take to help prevent your dog from contracting the disease. Before breeding your dog, both the male and female dog should be examined by a veterinarian and have a brucellosis test performed, so you will know if your dog is infected and will stop them from being infected by others. The test involves a simple blood test. Breeding facilities should have all new additions tested for brucellosis before bringing them onto the premises. These dogs should also remain isolated until a second negative test is obtained 4-6 weeks later. Dogs should not be bred if they test positive for brucellosis. Always keep your dog away from known carriers of the disease. Routine disinfecting of areas is also advised. Contaminated wet areas should be dried and disinfected with a 1% bleach solution. Isolation, testing, and euthanasia of confirmed infected dogs are the primary methods necessary to eliminate and prevent the spread of disease in a breeding facility. During the quarantine/isolati on period, breeding dogs should be housed separately. It is important to note that the majority of testing for canine brucellosis checks for the presence of antibodies in the blood. Most of these tests commonly produce false positive results and unfortunately dogs are euthanized based on those results. If a test presents with positive results, discuss with your vet other testing methods, such as a blood culture, to confirm a positive or negative result. Decisions based solely on one test alone can lead to an unnecessary euthanasia.
Symptoms of Brucellosis
The classic sign of brucellosis is abortion during the third trimester of pregnancy. Other signs include stillbirths, conception failures and litter reabsorption. Signs that can be seen in the male are inflammation of the epididymis, the prostate gland, infertile males with abnormal semen, testicles that decrease in size and of the sheath covering the testis. In both the male and female inflammation of the lymph nodes may be seen, lethargy (decrease in activity, depressed), loss of libido, premature aging. Many dogs will not show signs of this disease at all.
What are the symptoms of canine brucellosis in humans?
Brucellosis can be diagnosed by isolating and identifying the Brucellacanis organism or by a blood test. The most common way of diagnosing brucellosis is by the Rapid Slide Agglutination Test (RSAT). This test is very sensitive but is not very specific. This means that it detects very small amounts of bacteria but does not differentiate between closely related bacteria types. False positive results for brucellosis are frequently produced when using this test. If your dog tests negative for brucellosis when using the RSAT you can be confident that your dog does not have brucellosis. If your dog tests positive further testing should be done to verify that your dog does actually have brucellosis.
There currently is no reliable treatment for brucellosis. In some cases long term antibiotic therapy has been successful in treating it but in other cases the disease persists regardless. The antibiotic therapy used consists of a combination of multiple antibiotics including doxycycline, minocycline, and streptomycin. In most cases the antibiotics will reduce the bacteria load in the blood stream but will not fully destroy all the bacteria present. Relapse is common, even after continual use of antibiotics. Having your dog spayed or neutered is an option to control sexual transmission of the disease but is not a cure and your dog can still spread the disease as it does not remove the bacteria from the body. In most cases euthanasia is the only permanent way to stop the disease from spreading. Treatment is especially difficult in male dogs as the prostate gland and testicle is chronically infected. The only proven method for eradication in kennels is to test all dogs and eliminate the confirmed positives. In most cases euthanasia is the only permanent way to stop the disease from spreading.
Care for dogs with Brucellosis
If your dog has been diagnosed with brucellosis the first thing to do is quarantine them. This will help stop the spread of the disease. If you have other dogs in your house or kennel they should also be tested for brucellosis. The area where the infected dog was staying should be thoroughly cleaned with a disinfectant. Because brucellosis can be transferred from dogs to humans it is important to use caution when handling infected animals. Face masks, latex gloves, and eye protection should be worn when dealing directly with body fluids from infected dogs. If treatment is being pursued correct dosages and timing of antibiotics are important and your veterinarian’s instructions should be followed precisely.
If my dog has canine brucellosis, can I get sick too?