Assessing executive cognitive functions in sheep: a scoping review of recent literature on cognitive tasks

The study of cognitive processes in sheep (Ovis aries) has gained interest in recent years, particularly for their potential as a model species in translational medicine. This scoping review aimed to identify, classify, and describe cognitive tasks developed to assess executive functions in sheep. A literature search followed PRISMA guidelines and used CAB Abstracts, PubMed, and Scopus to identify studies on cognitive tasks in sheep from 1 January 2010, to 4 August 2025. The search yielded 2873 records; after removing duplicates and applying inclusion criteria, 20 studies were analyzed. Data on animal categories, test methods, and timing were collected. The selected studies were grouped by cognitive domain: memory and flexibility (13), sensory discrimination (6), and problem-solving (6). All studies describe specific testing apparatuses tailored to assess distinct cognitive functions, detailing materials, apparatus dimensions, and the importance of pre-test periods, as well as the necessity of a reward system. The review emphasizes ethical testing that minimizes animal stress, supporting welfare. Standardizing cognitive tests can improve reliability, and comparability while integrating neurobiology, ethology, and welfare knowledge advances research and livestock care.