Serum antibody response to canine parvovirus, canine adenovirus-1, and canine distemper virus in dogs with known status of immunization: Study of dogs in Sweden

Abstract
SUMMARY: Serum antibody titers to canine parvovirus (cpv), canine adenovirus-1 (cav-1), and canine distemper virus (cdv) were measured in dogs with known immunization status. The dogs represented 3 groups: nonvaccinated dogs < 12 months old; vaccinated dogs < 12 month old; and adult dogs > 12 months old. For practical reasons, the population from which the specimens were obtained could be considered as free from natural infection with cav-1 and cdv. In nonvaccinated dogs < 12 months old, antibodies against all 3 viruses were measured at the time the dogs were given their first vaccination. Altogether, 50.7% of the dogs had titer ≥ 1:10 to cdv, and 26.1 and 46.2% had titer ≥ 1:8 to cav-1 and cdv, respectively. The concentration of maternal antibody seemed to be of major importance for failure of immunization with use of inactivated cpv vaccine, but not with cav-1 and cdv vaccination. In dogs < 12 months old and vaccinated against cpv infection with inactivated virus, only 11.5% had titer ≥ 1:80. In dogs vaccinated against infectious canine hepatitis and canine distemper, 63.2 and 78.3%, respectively, had titer ≥ 1:16. In adult dogs > 2 months old and vaccinated against cpv infection, < 50% had titer ≥ 1:80, regardless of time after vaccination. There was no significant difference in titer between vaccinated and nonvaccinated dogs. Approximately 60% of these dogs had titer ≥ 1:16 to cav-1 at all time intervals after vaccination. There was only a weak correlation between decrease of titers and time; this correlation could be explained by the fact that a proportion of the dogs had been vaccinated with inactivated cav-1 virus. There was, however, no correlation between titer to cdv and time. The percentage of dogs with titer ≥ 1:16 was at least 60%.