Potential of Nail Cortisol for Welfare Assessment in Shelter and Owned Cats

Shelter cats often experience considerable stressors, such as confinement and unfamiliar surroundings, leading to welfare challenges. Evaluating and enhancing their well-being is crucial, and measuring cortisol levels in cats’ nails offers a minimally invasive method for assessing stress and welfare. This study compared nail cortisol concentrations (NCCs) between owned cats (OC), and shelter cats in favorable conditions (FS) and unfavorable conditions (UFS) in Thailand and Vietnam. Nails from 31 OC, 29 FS, and 27 UFS cats were collected twice, approximately 28 days apart, with details of living conditions recorded at the second collection. Nail clippings were processed for NCC measurement using the enzyme-linked immunosorbent assay technique. NCC levels of UFS cats were significantly higher than those of FS and OC cats in both collections, with no gender-based differences. NCCs positively correlated with dog exposure, and negatively correlated with space allowance, number of litterboxes, free-roaming time, air conditioning, and the presence and variety of enrichment (hiding places, elevated areas, outdoor views, scratching structures, and toys). These findings indicate that improved living conditions positively impact welfare, as indicated by NCCs. Nail cortisol can serve as a minimally invasive method for assessing cat welfare, particularly considering long-term factors, and offers valuable insights into the well-being of cats in various conditions.