Simple SummaryShelters are stressful environments for domestic dogs (Canis familiaris). Evaluating dogs’ welfare is crucial to improve their life condition and to promote a better management of shelters. The aim of this research was to analyse the physiological and behavioural responses of dogs in different environmental conditions. We conducted behavioural observations on 10 male dogs and collected faecal samples in order to determine the level of cortisol metabolites. Dogs were observed in four different cage conditions: (i) alone in a cage; (ii) alone in an enriched cage; (iii) in cage with conspecifics; (iv) in cage with regular interaction with humans outside the cage. The presence of conspecifics is the best way to reduce stress in shelter dogs. This research could provide some useful guidelines for managing shelters and improving dogs’ life condition.AbstractShelters are stressful environments for domestic dogs (Canis familiaris). Evaluating dogs’ welfare is crucial to improve their life condition and to promote a better management of shelters. We aimed at verifying which variables improved welfare in 10 shelter dogs ((hosted in the shelter “Centro cinofilo Caerite” in Bracciano (Rome)) by analysing their behavioural responses in different environmental conditions. Furthermore, faecal samples were taken to measure cortisol metabolites (CM), a non-invasive method to evaluate adrenocortical activity in dogs. Dogs were observed for a total of 400 h in 4 different cage conditions: (i) alone in a cage; ii) alone in an enriched cage; (iii) in cage with conspecifics; (iv) in cage with regular interaction with humans outside the cage. Alone in the cage situation showed highest frequencies of displacement activities (Friedman test: χ2= 13.32;p= 0.004). In contrast, being in the cage with conspecifics seems to reduce displacement activity frequency, as well as the level of faecal cortisol metabolites (Friedman test: χ2= 8.04;p= 0.045). Our results suggest that conspecifics’ presence is the best way to reduce stress in shelter dogs. This research could provide some useful guidelines for managing shelters and improving dogs’ life condition.