Abstract
Canine brucellosis is a critical problem in dogs leading to reproductive illnesses including abortion and infertility. Brucella canis significantly influences the reproductive organs targeting local lymph nodes (LN) and causing a fluctuating bacteremia. It may also have systemic effects in chronic cases. The aim of this study was to gain insight into the diagnostic characterization of B. canis-infected dogs using histopathological findings and bacterial isolation from different organs to further understand the pathogenic changes in canine brucellosis. We collected different specimens from 24 asymptomatic seropositive dogs, including 10 tissues (superficial inguinal LN, uterus, etc.), blood and urine. We performed an in-depth histopathological analysis and bacterial isolation to detect the pathogenic changes and presence of B. canis in the collected specimens. Of the 24 seropositive dogs, 20 were confirmed as true positives with B. canis cultured from more than one specimen. Within the bacteria-positive dogs, 15 (75%) showed remarkable histopathological findings in six kinds of tissues (submandibular LN, lung, liver, kidney, uterus, testis, epididymis), including granulomatous and suppurative lesions. The histopathological findings correlated with bacterial presence in a majority of the cases (66.7%). Dogs with histopathological lesions in the liver exhibited multifocal granulomas around the hepatic vein. Seven dogs had B. canis isolated from the uterus; one dog showing progressive endometritis with severe necrosis and brownish exudate in gross findings and a severe granulomatous pyoendometritis with inflammatory infiltration of neutrophils, lymphocytes, plasma cells. This study further defined the pathogenic characteristics of canine brucellosis, revealing bacteriological and histopathological findings. Moreover, it suggests that dogs infected with B. canis demonstrate significant systemic pathology as well as reproductive organ effects. Work supported by APQA B-1543081-2021-22-02.
