Seroprevalence of canine distemper in free-roaming dogs in buffer zone of Bardiya National Park, Nepal.

Canine distemper (CD), caused by Morbilivirus canis of Paramyxoviridae family, is a contagious and potentially fatal viral disease affecting a wide range of domestic and wild canid species. This study aimed to determine the seroprevalence of Canine Distemper Virus (CDV) and associated risk factors among free-roaming dogs in the buffer zone of Bardiya National Park (BNP), Nepal. A total of 91 serum samples were collected from free-roaming dogs and tested for CDV-specific IgG antibodies using an iELISA kit. The apparent seroprevalence was found to be 52.75% (95% CI: 42.5-63.0%), while the Rogan-Gladen adjusted true prevalence was 53.28% (95% CI: 42.92-63.64%). Among seropositive samples, 29.17% had high, 31.25% medium, and 39.58% low antibody titers, indicating mixed stages of exposure. Although older dogs (> 72 months) showed higher seropositivity (80%), no statistically significant association was observed between CDV seropositivity and age, sex, body condition score, and location (p > 0.05). The findings suggest that CDV is enzootic in the free-roaming dog population around BNP, representing a potential reservoir for viral spillover to vulnerable wildlife species such as leopards and tigers.