Sterilization Timing Effects on Lengths of Stay in Shelter Dogs and Cats with Positive Outcome

In 2023, an estimated 6.5 million pets entered one of the thousands of animal welfare organizations across the United States. Currently, animal shelters are experiencing a capacity crisis as an additional 900,000 animals have entered shelters since 2021 and have remained in care. Previous studies have attributed longer lengths of stay to many factors about the animal and shelter, including abnormal or problem behaviors, medical conditions and treatment, and available resources. Understanding how the timing of an animal’s sterilization surgery can affect its length of stay might aid in the development of evidence-based best practices regarding this procedure. The current study utilized records sourced by Shelter Animals Count, a nonprofit organization that maintains a centralized database of United States animal sheltering data, for the year 2023 to investigate what shelter and animal variables, including the timing of its sterilization surgery, affect dog and cat lengths of stay. Our analysis showed significant relationships between sterilization surgery timing and days in the shelter, such that adopted dogs and those that were transferred out for placement had the shortest lengths of stay when sterilized post-outcome, while adopted and transferred cats had the shortest lengths of stay when sterilized before their arrival to the shelter. Moreover, we uncovered relationships between an animal’s length of stay and how it arrived at the shelter and the animal’s positive outcome as well as the region in which the shelter was located and the type of positive outcome it experienced. In all, we found associations between sterilization surgery and length of stay, in addition to impacts of intake type and geographic region, that suggest the timing of this procedure could impact animal welfare and organizational resources, and warrants further investigation.