BACKGROUND: Brucellosis is a febrile zoonotic infection
and has worldwide distribution among humans as well as
animals. Although the seroprevalence of brucellosis in various
animals has been described in Iran, there is only one report on
equine brucellosis in the region. OBJECTIVES: This study was
carried out to determine the seroprevalence of brucellosis in
racing clubs and private horse owners in the south of Iran and risk
factors associated with the disease in horses. METHODS: 312
randomly selected equine serum samples were investigated for
the presence of antibodies against Brucella genus, using slide
agglutination by Rose Bengal plate test (RBPT), serum agglutination
test (SAT) and 2-mercaptoethanol (2-ME) test, using
whole cell antigen. PCR assay was also used for detection of
clinically suspected cases. RESULTS: Most seropositive horses
in this study were asymptomatic. The true seroprevalence of
brucellosis was found to be 9.9, 8 and 7% by RBPT, SAT and 2-
mercaptoethanol tests, respectively. All horses with history of
clinical signs (3.2% of all samples) had RBPT, SAT and 2-
mercaptoethanol positive results. It was also revealed that age,
sex and a history of contact with ruminants had no effect on
acquiring the infection in positive cases. In the PCR, one of the
three horses with fistula withers produced amplicon of 450 bp
fragment of wbo sequences specific to Brucella spp. field strain.
CONCLUSIONS: This study showed the seroprevalence of
brucellosis in horses of Fars province and it was indicated that
the PCR assay may be helpful in detection of clinically suspected
horses.