Brucellosis is a bacterial disease that affects many domestic animals such as pigs, cattle, and can also infect humans. The strains of brucellosis that originate from livestock were once developed as agents of biological warfare. In dogs it is transmitted primarily through breeding or sexual contacts, although it is also possible to contract the disease via contact with infected tissues. With the majority of pet owners who are not engaged in breeding, brucellosis is of less concern; however, any dogs that will be used for breeding must be regularly screened for the disease.
If humans contract the canine version of brucellosis, there will be flu-like symptoms that are usually not particularly severe. It is most frequently contracted by handling still-born pups without proper protection and disinfection. Human-to-human transmission is also possible, but extremely rare.
Symptoms and Diagnosis
In both sexes, the disease causes swollen lymph nodes, lethargy, and inflammations of the spleen or liver. In males there may be inflammation of the genitalia, abnormal sperms, and decrease in fertility. In females there may be spontaneous abortion late in pregnancy (45 to 55 days), which is sometimes the only sigh of the infection. In many cases infected dogs do not appear to be sick. Untreated brucellosis may become chronic, which in the long term will cause sterility and other health problems such as arthritis and eye inflammation.
Since the symptoms may be difficult to detect or non-existent, the only way to diagnose the disease is through regular immunological tests. The tests are performed in two phases: a screening test to identify negative dogs, and a further test to detect false positives. It is recommended for dogs that are in active breeding programs be tested for brucellosis every six months.
Since the infection is caused by bacteria, it can be treated with antibiotics. However, relapse is common since it is difficult to fully eliminate the bacteria from an infected animal. Therefore, any dog tested positive for brucellosis must be isolated from other breeding dogs, as well as spayed or neutered to prevent further transmission of the disease through breeding. While some dogs may have to remain on antibiotics for life, it is possible for some dogs to naturally recover from the infection. However, natural recovery can take years, during which the infected dog will remain contagious. For dog breeders, diligent testing and good disinfection practices are effective ways to keep the breeding stock healthy and free of brucellosis.