Trends in Intake, Length of Stay and Outcome Data in a Portuguese Animal Shelter Between 2018 and 2024

Municipal animal shelters play a crucial role in rescuing abandoned animals, managing free-roaming populations, and promoting animal welfare. This seven-year retrospective study analyzed 2291 animals (1132 dogs, 1159 cats) admitted to a Portuguese municipal shelter (CVM Feira) between 2018 and 2024 to identify predictors of live outcomes. Descriptive and regression analyses were performed on 1325 adoptable animals. Adoption occurred for 58.9% of these animals, while 41.1% remained in long-term housing, reflecting growing shelter capacity pressures. Length of Stay (LOS) was the strongest predictor of adoption, with extended stays markedly reducing adoption odds and contributing to overcrowding. For dogs, female sex and owner or animal protection association (APA) surrender increased adoption likelihood. Microchipped animals were 71 times more likely to be returned to their owners, although only a small proportion entered the shelter with identification. The overall Live Release Rate (LRR) was 79.7% and Save Rate (SR) 84.7%, highlighting effective life-saving efforts, while the Population Balance Calculation (PBC) of 75.6% revealed challenges in population flow-through. These findings provide evidence that data-driven strategies, including reducing LOS, enforcing microchipping, and applying species-specific management, are essential to optimize municipal shelter operations and improve animal welfare, with insights applicable to broader European and international contexts.