Canine brucellosis caused by Brucella canis (B. canis ) is a infectious disease responsible for abortions in females and orchitis in males. The prevalence of the disease is variable according to the region and diagnostic methods used. B. canis, in Brazil, has been detected through serology as well bacteriology demonstrating the emergency of the disease.

This paper reports the isolation of B. canis from a canine foetus necropsized in the animal infectious disease sector at School of Veterinary Medicine and Zootechny -UNESP/Botucatu-SP, Brazil. The abortion occurred at the last period of gestation and the female had no clinical symptoms. This animal came from a little kennel, without brucellosis and reproductive control and where several dogs resulted serologically positive to B. canis. The foetus around 55 days in development was necropsized. The fetus was intact, and macroscopic evaluation showed hepatomegaly. Fragments of fetal kidneys, lung and liver as well female blood and vaginal swab were cultured on defibrinated sheep blood agar (5%) and MacConkey agar, in aerobic and microaerophilic conditions. Pure cultures of Gram-negative coccobacilli were isolated from all fetal tissues in sheep blood agar72hs after. The isolate was oxidase-positive, urease-positive, thionin and basic fuccine positive and H₂S and CO₂negative. These microorganisms were characterized as Brucella canis.

Female serum was obtained two weeks after the abortion and resulted positive to rapid agglutination test with and without 2-mercapthoetanol (DTec-CB- Symbiotics) and immunodiffusion agar test but negative to Brucella abortus when tested by Rose Bengal test.

Serological positivity in kennels correlated with absence of canine brucellosis control and good reproductive measures has been reported by several authors. The isolation of B. canis reported here was correlated with serological positive results in the female as well in the kennel associated with absence of adequate reproductive and hygienic conditions and brucellosis control reinforcing the importance of these aspects in maintaining the disease.

The zoonotic potential of the disease must be reinforced as B. canis can be eliminated by reproductive secretions and abortion representing a risk to public health.