Animal Hoarding: a systematic review

Animal hoarding is a special manifestation of Hoarding Disorder, characterized by the accumulation of animals and failure to provide them with minimal care. The main objective of this systematic review is to evaluate the characteristics of animal hoarding with a focus on the profile of affected individuals and accumulation behavior features. A systematic search of the literature using the electronic databases MEDLINE, SCOPUS and LILACS was conducted until October 2022. We included case series (n ≥ 10) and cross-sectional studies assessing animal hoarding. 374 studies were initially retrieved. Most studies were classified as poor quality and significant risk of bias. 538 individuals with animal hoarding were evaluated. These individuals were predominantly middle-aged, unmarried females who lived alone in urban areas. Most residences presented unsanitary conditions. Recidivism rates varied from 13-41%. Cats and dogs were the main hoarded species, mostly acquired through unplanned breeding and found with lack of hygiene; diseases; injuries; and behavioral problems. Animal carcasses were found in up to 60% of the properties. Animal hoarding is a complex condition that requires urgent attention. More research is necessary to develop effective strategies that can save community resources, improve animal and human welfare, and prevent recidivism.