Test reagents and procedures

All test reagents used in this study (RSA antigen, RBT antigen, SAT antigen, cELISA kit) were supplied by the Animal and Plant Health Agency (APHA) (Surrey, United Kingdom) and standardized according to the stipulations set by the OIE [23]. Serum samples were examined by RSA, RBT, SAT and cELISA for antibodies to Brucella sp. The RSA test and RBT were performed as described by Amin et al. (2012) [24]. Briefly, 30µl of serum sample was mixed with equal volume of antigen on a white enamel plate. The plate was rocked and serum samples that showed agglutination were recorded as sero-positive to Brucella sp. Positive samples by RSA and RBT were further respectively analysed using SAT and cELISA as previously described [24, 25]. Data were analyzed using Stata versions 12. Frequencies were generated and Chi square test was used to explore variables potentially associated with Brucella infection among dogs. The level of statistical significance was set at p < 5%. Variables significant at 10% on bivariate analysis were entered into the logistic regression model.