Molecular and serological investigation of Brucella species in kennel and farm dogs in Iran

Introduction

Brucellosis is still a significant emerging threat to public health, as it can infect humans, wild, domestic animals, and livestock. Hence, the current study aims to determine the frequency of canine brucellosis (CB), its relationship with clinical findings and reproductive disorders in kennel and farm dogs, and its importance on public health.

Materials and methods

From January 2022 to December 2023, a total of 150 blood samples were taken from 100 adult dogs in breeding kennels and 50 shepherd dogs in breeding farms in Kerman, Iran. Rose Bengal test (RBT) and Wright tests were used for the primary screening of Brucella abortus (B. abortus) and Brucella melitensis (B. melitensis) species, and conventional IS711-based PCR and real-time polymerase chain reaction (RT-PCR) were performed to determine the Brucella genus and species in all samples.

Findings

In kennel dogs, 34 % (34/100) had a history of breeding disorders, and 30 % (30/100) were RBT-positive. Moreover, B. canis and B. abortus species were detected in kennel dogs. Among farm dogs, 16 % (8/50) had a history of breeding disorders, and 28 % (14/50) were RBT positive. Additionally, B. canis, B. abortus, and B. melitensis species were detected in farm dogs. Feeding with unpasteurized milk was significantly related to a positive RBT in kennel dogs (p = 0.009), and there was a significant correlation between breeding disorders and seropositivity in kennel (p = 0.045) and farm dogs (p = 0.03).

Conclusion

The current study represents a significant advancement in understanding CB in Iran by the first molecular detection of B. canis, revealing B. melitensis and B. abortus as important pathogens in kennel and farm dogs and highlighting the public health significance of disease in Iran.