C anine brucellosis is caused by the bacterium Brucella canis. Reproductive disorders such as late abortion, stillbirth, epididymitis, and sperm anomalies are most frequently observed (1). Other clinical signs are lymphadenitis (1,2) and musculoskeletal disease (e.g., discospondylitis) (3). In addition, the infection can remain subclinical (2). B. canis is mostly transmitted vertically from bitch to offspring or venereally through vaginal discharge and semen; urine has also been implicated as a possible mode of transmission (1,4,5).B. canis is a zoonotic pathogen; humans can become infected through direct contact with secreta and excreta of infected dogs (6,7) or through laboratory exposure (8,9). Clinical signs in humans vary from subclinical infection (10) to fever, malaise, splenomegaly, and lymphadenopathy (7). Human cases of B. canis infection are reported infrequently. However, the prevalence of human B. canis infections is probably underestimated; the diagnosis might be missed because of nonspecifi c clinical signs and the absence of accurate serologic tests for B. canis antibodies in humans (6,11). In the United States, a seroprevalence of 3.6% was found among persons occupationally exposed to dogs. Two seropositive persons had clinical symptoms of brucellosis, and both reported contact with B. canis-seropositive dogs (10). In addition, an outbreak involving 6 seropositive persons, 5 of whom had clinical symptoms, was described after contact with a seropositive litter (6). In general, B. canis appears to cause less severe clinical symptoms in humans than other Brucella spp. (12). However, the public health relevance of B. canis needs further investigation before a proper risk assessment can be performed.B. canis is considered endemic in the southern United States, Central America, and South America and has been reported from Canada, Asia, Africa, and Europe (7,13). Sporadic cases originating from northwestern Europe have been reported and were at least partially caused by importing an infected dog (13,14). Recent papers have expressed concerns about the introduction of B. canis in countries to which it is not Transboundary Spread of Brucella canis through Import of Infected Dogs, the Netherlands,