This document discusses companion animals and neutering as it relates to street dogs. It notes that street dog populations come from owned dogs that roam or are abandoned, as well as from natural reproduction among roaming dogs. This causes problems like disease transmission, nuisance, and welfare issues. Impounding and dumping dogs are ineffective solutions and cause further issues. The most effective approach is TNVR (Trap-Neuter-Vaccinate-Release), which involves sterilizing dogs to control populations, vaccinating against rabies, treating other diseases, and releasing them back to their locations. The document provides some case studies of successful TNVR programs and discusses the role of international training centers in sharing knowledge between animal welfare charities worldwide