Research Article: The first case of Brucella canis in Sweden: background, case report and recommendations from a northern European perspective

Date Published: March 27, 2012

Publisher: BioMed Central

Author(s): Bodil Ström Holst, Karin Löfqvist, Linda Ernholm, Karin Eld, Maria Cedersmyg, Gunilla Hallgren.


Infection with Brucella canis has been diagnosed in Sweden for the first time. It was diagnosed in a three-year-old breeding bitch with reproductive disturbances. Fifteen in-contact dogs were tested repeatedly and all of them were negative for B. canis. The source of infection could not be defined. The present article describes the case and the measures undertaken and gives a short review over B. canis. Recommendations on how to avoid the infection in non-endemic countries are given.

Partial Text

Until 1994, Sweden had a quarantine requirement for all dogs entering from abroad, except for dogs from Norway. Norwegian dogs were allowed to enter without any requirements at all since Norway has had the same epidemiological status as Sweden for several decades. From 1994 to 2004, however, dogs from EU and EFTA countries were allowed entry without quarantine if in possession of an identity mark, rabies vaccination, rabies antibody titre control and certain other prophylactic treatments. An import license, amongst other documentation, was required. In 2004, the new European pet regulation 998/2003 came into effect allowing entry in combination with certain national requirements. For dogs from EU and EFTA countries only identity marking, rabies vaccination, rabies antibody testing, deworming and a pet passport was needed. These changes in regulations facilitated travelling of dogs between Sweden and other European countries, especially those within the European Union (EU). In addition, it led to an increased responsibility for dog owners to protect their travelling dogs against unfamiliar infections that did not exist in Sweden.

In December 2010, a 3-year-old American Staffordshire terrier imported from Poland, expecting her first litter, was brought to the Regional Animal Hospital of Helsingborg, Sweden. She was 46 days pregnant but although her general condition was good, she had a green vaginal discharge. An ultrasonography was performed which revealed that all pups were dead. The bitch was aborted with aglepristone and prostaglandins, and also received amoxicillin. Hematology showed mild leukocytosis and moderate eosinophilia. Bacterial culture from the vagina showed no bacterial growth. The bitch was monitored with ultrasonography and clinical examinations for the following weeks. Her general condition was good and the discharge ceased rapidly. No foetal parts could be identified in the discharge.

The bitch was imported as a young dog to Sweden from Poland. The first male dog that she was mated to, from Serbia, has a history of bitches not conceiving after mating, including the present bitch. There are several causes for bitches not to conceive, including poor semen quality due to infection with B. canis. This male dog has been included in the contact tracing as he now resides in Sweden.

A typical case of B. canis in a dog with reproductive disturbances has been diagnosed in Sweden. Handling of the case by the practicing veterinarian and by the authorities is described. Results from the contact tracing indicated that the infection most probably has not spread within the country. The source of infection could not be identified. Recommendations on how to avoid introduction of B. canis into non-endemic areas are given.

AGID: Agar gel immunodiffusion; CFU: Colony forming units; ELISA: Enzyme-linked immunosorbent assay; LFIA: Lateral flow immune-chromatographic assay; 2-ME: 2-mercapto-ethanol; PCR: Polymerase chain reaction; RSAT: Rapid slide agglutination test.

The authors declare that they have no competing interests.

BSH compiled the information, initiated and drafted the manuscript, KL handled the case including communication with authorities and drafted the manuscript, LE and GH handled the contact tracing at the National Veterinary Institute and MC was responsible at the Swedish Board of Agriculture. KE was responsible for the bacteriological parts. All authors read and approved the final manuscript.