Duration of serological response to canine parvovirus‐type 2, canine distemper virus, canine adenovirus type 1 and canine parainfluenza virus in client‐owned dogs inAustralia

Abstract

ObjectiveTo determine whether client‐owned dogs in Australia, last vaccinated withCanvac® vaccines containing canine parvovirus‐type 2 (CPV‐2), canine distemper virus (CDV), canine adenovirus type 2 (CAV‐2) ± canine parainfluenza virus (CPiV) at least 18 months ago, were seropositive or responded serologically to revaccination.MethodsA total of 235 dogs were recruited from 23 veterinary clinics, representing a variety of breeds, ages and time since last vaccination (TSLV: range 1.5–9 years, mean 2.8 years). Dogs had a blood sample taken and were revaccinated on day 0. A second blood sample was taken 7–14 days later. Blood samples were assessed for antibody titres toCPV‐2 (by haemagglutination inhibition) andCDV,CAVtype 1 (CAV‐1) and CPiV (by virus neutralisation). Dogs with a day 0 titre >10 or a four‐fold increase in titre following revaccination were considered to be serological responders.ResultsThe overall percentage of dogs classified as serological responders was 98.7% forCPV‐2, 96.6% forCDV, 99.6% forCAV‐1 and 90.3% forCPiV.ConclusionsThese results suggest that the duration of serological response induced by modified‐live vaccines againstCPV‐2,CDV,CAV‐1 andCPiV, includingCanvac® vaccines, is beyond 18 months and may extend up to 9 years. Accordingly, these vaccines may be considered for use in extended revaccination interval protocols as recommended by current canine vaccine guidelines.