The problem of homelessness of dogs and cats is addressed mainly through spay and neuter clinics. Reproduction control is particularly important for the population of dogs and cats in rural areas. The safety of general anesthesia is one of the most important elements of surgical procedures, especially when working under field conditions. The aim of the study was to describe an anesthetic protocol used on dogs and cats during mass castration and sterilization programs which will be suitable for Polish conditions. The data were collected in the years 2009-2014 for 130 animals that underwent castration or sterilization. General anesthesia during surgical procedures was based on the use of dexmedetomidine, butorphanol, ketamine, and midazolam. The protocol was evaluated for its safety. We also compared it with anesthetic protocols used during mass castration and sterilization programs for dogs and cats in other countries. The number of complications was very low: apnea during anesthesia was observed in one patient, that is, in 0.99% of the treated animals. The selected protocol was assessed as safe, simple to use, and cost-effective.