Research Communications of the 27(th) ECVIM-CA Congress: Intercontinental, Saint Julian's, Malta, 14th to 16th September 2017

Disclosures: No disclosures to report. Distemper, infectious canine hepatitis and parvovirosis are lifethreatening diseases due respectively to canine distemper virus (CDV), canine adenovirus virus (CAV)-1 and canine parvovirus (CPV). The maintenance of the serological response post vaccination is often used to evaluate the protective status of a dog. However, as live vaccines stimulate mainly the cell-mediated pathway of the immune system, this method may underestimate the real duration of efficacy of these vaccines. The study aim was to evaluate the efficacy of the attenuated CDV, CAV and CPV strains of the multivalent Canigen TM DHPPi/L vaccine (Virbac, France) after experimental infections performed at three years after the first annual booster. Forty seven SPF Beagle puppies, males and females, participated in the study. Puppies were allocated to either the vaccinated group (Group 1, n = 23) or the unvaccinated group (Group 2, n = 24). Puppies of Group 1 received Canigen TM DHPPi/L vaccine, formulated at minimum titer for the live components, for primary vaccination with two injections at a three-week interval (respectively at 9 and 12 weeks of age) and for the first annual booster. Blood samples were taken on several occasions for serological follow-up. CDV, CAV-1, CPV-2 and CPV-2c antibody titers were measured by seroneutralization tests (SN). After vaccination, SN antibody titer ≥ 10 0.7 for both CDV and CAV-1 and ≥ 10 1.17 for CPV-2 variants are considered as positive. At three years after the first annual booster, dogs of both groups were administered either a pathogenic CDV (n = 10) or CAV-1 (n = 12) or CPV-2c (n = 12) strain and followed for the appearance of any typical sign of the related disease for 21 days. Vaccinated dogs with the lowest SN titers were selected to receive the pathogenic agents.