Capturing free-roaming dogs for sterilisation: A multi-site study in Goa, India

Sterilisation and rabies vaccination programs seek to manage free-roaming domestic dog (Canis familiaris) populations with the aim to reduce inter-species disease transmission and conflicts. As effective, permanent, remotely-administered options are not yet available for sterilisation, and oral vaccination is not yet commonly used; free-roaming dogs are typically captured for these interventions. There is a paucity of information describing how dog capture rates change over time within defined areas following repeated capture efforts. This data is needed to allow efficient dog capture programmes to be developed. Using spatial co-ordinates of dog capture, we characterise where dogs are more likely to be captured in six catch-sterilise-release campaigns, in Goa state, India. Combining capture numbers with population survey data collected in five sites, we document the increasing difficulty of catching entire (non-sterilised) dogs as sterilisation coverage increases and demonstrate how this leads to increased unit costs. Accounting for the extra resources required to capture dogs when sterilisation coverage is high will improve estimation of the resources required to manage free-roaming dog populations and assist in planning the most efficient intervention strategies.