Serological Study of Canine Parvovirus-2 Antibody Titers

Canine parvovirus 2 (CPV-2) is the causative agent of one of the most contagious and fatal gastrointestinal infections in domestic and wild canids. The rapid spread of the infection makes this disease a serious challenge, especially in dog shelters and kennels. Disease control is accomplished by the application of modified live virus vaccines to obtain long-term immunity. However, post-vaccinal efficacy and immunity can significantly vary depending on the vaccination protocol, health status of the animals and the presence of maternal antibodies and with regard of the virulence of the circulating antigenic variants.

Establishment of the factors which can induce vaccination failure can contribute to better management and control of the parvovirus infection. Rapid antibody tests for the evaluation of immune status before or after vaccination can be used as a valuable marker for disease protection level and a guideline for revaccination strategies in healthy dogs.

Aim

The aim of the study was to determine the CPV-2 post vaccination antibody titers in a community of young shelter dogs, vaccinated according to a three-dose regimen with the help of the rapid kit VacciCheck.

Methods

The study consisted of 320 blood serum samples from healthy mongrel dogs found in a private dog shelter. The blood sampling was conducted 14 days after the last vaccine booster. The estimation of the parvovirus antibody titers was assayed using ImmunoComb® Canine VacciCheck.

Results reading

The antibody concentration is defined by the color intensity of the resulting spots of the rapid test and is compared with the “S” units on a scale from 0 to 6. An “S” value of 3 (S3) was assigned as the positive serum titer which can provide protective immunity. Samples showing 0-2 “S” units, were interpreted as non-immunized and unprotective.

Results

Protective antibody titers were demonstrated in 90% (288/320) of the studied animals while 10% (32/320) lacked post vaccination protection based on their CPV antibody levels. All dogs with IgG titers of 3 “S” or more were estimated as having vaccination protection, based on the manufacturer’s recommendation (Figure 1).

Figure 1: Number of shelter animals with different “S” units after CPV vaccine applications.

Conclusions

Based on the results of the current survey, it is concluded that the three-regimen CPV vaccination protocol can provide a successful post vaccination cover in the majority of shelter dogs. However, the relatively high vaccination failure rate indicates possible gaps in the development of sustainable herd immunity.