Rt-PCR Detects Canine Distemper Virus in Asymptomatic and Non-Vaccinated Puppies

Abstract

The objective of the present study was to use reverse transcription-polymerase chain reaction (RT-PCR) for canine distemper virus screening in puppies with asymptomatic canine distemper. Blood samples were taken from 12 non-vaccinated asymptomatic puppies, 10-45 days of age; of mixed breeds, ages, and sexes. Vero cells infected with canine distemper virus strain Lederle were used as the positive control. Using acid guanidinium thiocyanate-phenol-chloroform extraction, RNA was isolated and treated with a DNA-free™ kit (Ambion Inc., Foster, California, USA). Primers specific to the nucleocapsid protein coding region gene of canine distemper virus were designed and were able to amplify a fragment of 319 bp. Another target fragment of canine S26 (75 bp) was utilized as the endogenous control. Eight animals (67%) were positive and 4 (33%) were negative in a total of 12 animals analyzed. In conclusion, accurate diagnosis for canine distemper virus in early stages of infection using RT-PCR enhances identification of any infected puppies to be quarantined and prevents spread of disease.