Welfare of farmed silver foxes (Vulpes vulpes) housed in sibling groups in large outdoor enclosures

Abstract

The aim of the present study was to evaluate the effects of housing farmed silver foxes in large outdoor enclosures with less abundant human contacts on some behavioural and physiological welfare parameters. Farmed silver fox cubs were housed either singly in traditional fox cages or in sibling groups in enclosures. Mass of adrenals, serum cortisol level after adrenocorticotrophic hormone (ACTH) administration and stress-induced hyperthermia, as well as 24-h activity measures and the number of bite scars, were used to draw conclusions on the welfare effects of housing farmed silver foxes in the two experimental housing systems. The housing system had significant effects neither on the serum cortisol level after ACTH administration nor on the mass of adrenals. This result shows that intra-group social tension and non-habituation to humans, both leading to increased long-term stress in foxes housed in large outdoor enclosures, can be partly overcome by, respectively, altering the group composition and keeping the cubs for a longer time in cage conditions with close human contact. However, a large number of bite scars and increased stress-induced hyperthermia (SIH) in the foxes housed in enclosures, indicating an acute stress response to the presence of humans, may not be overcome. Furthermore, the 24-h activity rhythm changed in the foxes housed in large enclosures resembling, especially in November, the nocturnal activity pattern of the wild red fox, indicating that the foxes in enclosures became at least to some extent feral. Key words: Activity rhythm, aggression, hypothalamic-pituitary-adrenal axis, human-animal relation, stress-induced hyperthermia, Vulpes vulpes