Canine brucellosis is an infectious disease caused by the bacterium Brucella canis, which mainly affects the reproductive apparatus of both dogs males and females.

The natural transmission of brucellosis occurs in various ways. The bacterium is transmitted by oronasal contact with infected fluids (during oestrus, birth or abortion) in females and through seminal fluid and urine in males.

Puppies can be infected in utero, as well as through delivery or lactation and may remain intermittently bacteraemic for years.

Infection may occur also by iatrogenic means (contaminated syringes) and blood transfusions.

The prevalence of infection varies according to age, breeding conditions, breed and geographical region. Pets in urban environments have a lower prevalence than stray dogs in economically depressed areas. Labrador and the Beagle have a higher prevalence among the breeds