Risk of canine distemper virus vaccination of domestic dogs in giant panda habitat to giant pandas

The giant panda (Ailuropioda melanoleuca), a unique relic species in China and a global biodiversity conservation symbol, faces the threat of canine distemper virus (CDV). Vaccinating domestic dogs in panda habitats against CDV is crucial, yet the associated risks remain understudied. We investigated the safety of CDV vaccination in 69 domestic dogs within panda habitats, employing enzyme-linked immunosorbent assay for CDV antibodies and quantitative reverse transcription polymerase chain reaction for viral RNA, a marker of viral shedding. Results revealed that vaccinated dogs posed a risk through viral shedding, mainly starting from the ninth day post-vaccination. Unvaccinated dogs exhibited increased CDV antibodies and subsequent shedding, with phylogenetic analysis confirming infection from vaccinated dogs in shared kennels. Dogs with higher initial antibodies displayed reduced shedding and a markedly abbreviated shedding duration (6.7 days) than those with lower initial antibodies (9.8 days). Habitat area analysis revealed substantial overlaps between domestic dogs and wild giant pandas in two nature reserves in China. To safeguard wildlife, particularly giant pandas, we recommend restricting vaccinated dogs' activity for at least three weeks post-vaccination, complementing existing management practices. We advocate collaborative efforts among local authorities, reserve management and villagers for effective vaccination and post-vaccination management of domestic dogs.