Comparative evaluation of clinical samples from naturally infected dogs for early detection of canine distemper virus

Early detection of canine distemper (CD) is critical for appropriate and timely treatment. The present study included 45 suspected cases with respiratory signs for a comparative evaluation of clinical samples in the early detection of canine distemper virus (CDV). Thirty-four dogs exhibited digestive system involvement, but none showed any neurological symptoms. Clinical progression of CD, based on age, sex, vaccination status, disease, and clinical findings, was observed. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect viral nucleoprotein RNA in plasma, conjunctival and nasal swabs. Only 10 dogs were positive for CDV infection. Among the 45 dogs, CDV RNA was detected in 5, 6, and 10 dogs using plasma, nasal and conjunctival swabs, respectively. The results suggest that the incidence of CD is independent of age and may involve secondary infections. For early detection of CDV, conjunctival swab is the most reliable sample (P < 0.05), as compared to nasal swab and plasma.