Molecular and Immunological Investigation of Canine Distemper Virus (CDV) and Its Co- Infection with Canine Parainfluenza Virus Type 2

Background and Objective: Canine distemper (CD) is a highly transmissible serious disease of carnivores. Distemper virus has immunosuppression effects, which, in turn, could lead to opportunistic infections. The present study was performed to detect CDV by the genomic and immunological methods and investigate its co- infection with canine parainfluenza virus type 2 (CPiV-2). Materials and Methods: In this study, which was conducted from Spring 2018 to Winter 2019, samples of blood, eye, respiratory, and digestive system were collected from 50 dogs suspected to CDV (group 1: symptomatic dogs) as well as 50 seemingly healthy dogs (group 2: asymptomatic dogs). Rapid distemper immunochromatography kit was applied for the primary detection of CDV. RT_PCR test was also performed using special primers for molecular investigation. Results: Results of immunochromatography showed twenty nine and one positive cases among dogs suspected to CDV and seemingly healthy dogs, respectively. After RT_PCR assay, in the first group, 37 samples were reported as CDV positive and 11, CpiV-2 positive. Furthermore, three CDV- and one CpiV-2-positive cases were found in the second group. Besides, the frequency of CDV and CpiV-2 co-infection was 4%. Conclusion: In the present study, using statistical tests, we observed no association between distemper and CpiV-2.