Background: Brucellosis is one of the most important and common diseases among humans and animals, with great health and economic significance.Objectives: This study aimed to investigate some risk factors of brucellosis infection in Iranian dairy farms.Methods: This study is a herd-level case-control study on dairy farms. Case dairy farms (95 dairy farms) included all registered cases of disease during 14 months of studying with at least one positive serum cow (Rose Bengal, Wright, and 2-mercaptoethanol tests consecutively) and control dairy farms (95 dairy farms) in the condition of at least two disease-free years were selected and matched due to the capacity, and geographical area with case dairy farms. The obtained data were analyzed by the multivariate conditional logistic regression test and SPSS software, version 20.Results: According to the statistical relationship between studying independent variables and brucellosis infection in herd, the hygiene and disinfection of watering points (washing at least three times a week and using detergent or disinfectant) reduce the risk of brucellosis infection (OR=0.04, 95% CI, 0.003%-0.499%) and factors such as the history of abortion (OR=7.01, 95% CI, 1.51%-32.59%), the replacement of livestock from outside (OR=7.87, 95% CI, 1.07%-58.07%) and introducing new livestock during last 12 months (OR=7.27, 95% CI, 1.20%-43.90%) increase the risk of brucellosis infection.Conclusion: More serious attention to rancher training, the observance of hygienic principles, and legal restriction of livestock displacement are among the recommended strategies to prevent brucellosis infection on the farm.

BACKGROUND: Canine brucellosis may occur due to Brucella spp. other than Brucella canis. Brucella bacterium is transferred between dogs, ruminants, and humans. Therefore, there is a need for vaccinating the hosts of Brucella, especially dogs. OBJECTIVES: The present study evaluates the efficacy of Rev.1 against B. melitensis in experimentally infected dogs. METHODS: Twelve Brucella-negative dogs were divided into two groups of test and control. The animals in the experimental group were vaccinated with Rev.1. After vaccination, sera of the dogs were tested by the standard tube agglutination test (STAT) and Rose Bengal test (RBT). Five months following vaccination, dogs in both groups were inoculated with 3×109 CFU of B. melitensis biotype 1. Serum samples were taken after inoculating the bacteria and were examined using the STAT and RBT. The specimens of lymph nodes and reticuloendothelial organs were collected for bacteriological culture. RESULTS: After the inoculation of Brucella, the antibody titer was significantly higher in the control dogs than in the experimental group. B. melitensis biotype 1 was isolated from all the control dogs, but it was isolated from three dogs in the test group. CONCLUSIONS: According to the findings of the current study, we recommend further studies on the immuniza-tion of dogs with the Rev.1 vaccine along with vaccinating small ruminants.