P8-11 Brucella canis serological survey in kennel dogs in North of Italy: case reports and preliminary data

Abstract

Canine brucellosis is a worldwide infection and zoonotic disease caused by Brucella canis (Bc), which major public health concern is due to close contact between dogs and humans. In dogs, brucellosis most commonly manifests with reproductive symptoms, lymphadenopathy, osteoarticular and neurological disorders, although the occurrence of asymptomatic and chronic infections are frequently reported. The present study aims to assess the seroprevalence in 227 kennel/free-ranging dogs, 30% female and 70% male dogs, average age 5 years old (range 1-16 Y/o), enrolled within the Ricerca Corrente IZSVE 12/19. The dogs were screened for Bc specific antibodies through a microplate serum agglutination tests (mSAT). Dog’s sera were tested using two-fold dilutions (from 1:20 to 1:640) and incubated for 48 hours at 37°C. In case of serologic titers ≥1:20, samples were submitted to the National and WOAH Reference Laboratory for Brucellosis, wherecomplement fixation test (CFT), immunofluorescence test (IF) and bacterial isolation from blood and urine were attempted. Moreover, PCR targeting Brucella spp. genes was performed with DNA extracted from the clinical samples. Results reported an overall serologic prevalence of 1.77 % (4/227). Among the positive animals, one dog (entire male, 7 Y/o, mixed breed) with a concurrent parasitic disease (Trichuris spp.) was found positive for B. canis antibodies (mSAT 1:40) and negative for the bacterial isolation: this dog was found seronegative one month later. The second significant case was a dog (entire male, 5 Y/o, Rottweiler) with testicles decreased in volume, reporting a positive serology (mSAT 1:20, CTF 1:10, IF 1:80) and negative bacterial isolation. The dog was re-tested after one month: mSAT 1:20, CTF negative, IF 1:40, negative bacterial culture (blood and urine), and borderline positivity for real time PCR Brucella spp. This dog was consequently neutered and further investigations are ongoing. Currently, prevention and control of canine brucellosis are not easily achieved, especially due to the difficulty in identifying infected dogs: the development of novel diagnostic methods and hopefully of specific regulations will represent a crucial point for surveillance of canine brucellosis, and raising awareness among human health in a One-Health perspective. Funding: Ricerca Corrente IZSVE 12/19, Italian Ministry of Health.