Brucelosis canina en Valdivia, Chile Estudio serológico y bacteriológico en perros de ciudad1

Canine Brucellosis: An Update

Canine brucellosis is an infectious and zoonotic disease caused by Brucella canis, which has been reported worldwide, and is a major public health concern due to close contact between dogs and humans. In dogs, canine brucellosis manifests with abortion outbreaks, reproductive failure, enlargement of lymph nodes, and occasionally affects the osteoarticular system, although the occurrence of asymptomatic infections in dogs are not uncommon. In humans, the disease is associated with a febrile syndrome, commonly with non-specific symptoms including splenomegaly, fatigue, and weakness. Infection of dogs occurs mostly by the oronasal route when in contact with contaminated tissues such as aborted fetuses, semen, urine, and vaginal secretions. In humans, contact with contaminated fluids from infected dogs is an important source of infection, and it is an occupational risk for veterinarians, breeders, laboratory workers, among other professionals who deal with infected animals or biological samples. The diagnosis in dogs is largely based on serologic methods. However, serologic diagnosis of canine brucellosis remains very challenging due to the low accuracy of available tests. Molecular diagnostic methods have been increasingly used in the past few years. Treatment of infected dogs is associated with a high frequency of relapse, and should be employed only in selected cases. Currently there are no commercially available vaccines for prevention of canine brucellosis. Therefore, development of novel and improved diagnostic methods as well as the development of efficacious and safe vaccination protocols are needed for an effective control of canine brucellosis and its associated zoonotic risk.

Canine brucellosis

This review discusses the prevalence, etiology, pathogenesis, clinical findings, diagnostic methods, therapy, management and public health considerations of Brucella canis infection in dogs. Canine brucellosis is a contagious infection produced by a gram-negative coccobacilus called Brucella canis. The main sources of infection are vaginal fluids of infected females and urine in males. Routes of entry are venereal, oronasal, conjunctivae mucosa and placenta. The most significant symptoms are late abortions in bitches, epididymitis in males and infertility in both sexes, as well as generalized lymphadenitis, discospondylitis and uveitis. Diagnosis is complex because serology can give false positive results and chronic cases can give negative results, needing to be complemented with bacteriological studies. No antibiotic treatment is 100% effective and the infection often recurs in animals apparently treated successfully. Infected animals must be removed from the kennels and no longer used for breeding. Preferably, males should be castrated and females spayed. Human contagion is not frequent, although it has been reported, and is easily treated.