Haematological and biochemical responses of red foxes(Vulpes vulpes)to different capture methods and shooting

Abstract

AbstractThis paper sought to determine whether common haematology and blood biochemistry values might assist in determining the relative welfare outcomes arising from the capture of red foxes(Vulpes vulpes)by treadle-snares, Victor Soft Catch® (VSC) #3 traps, cage traps, netting and sampling by shooting. Compared to all other capture methods and shooting, treadle-snared foxes had significantly higher mean albumin (ALB), creatine kinase (CK), red cell count (RCC), neutrophil to lymphocyte (N:L) ratio, sodium (Na), total protein (TP), white cell counts (WCC) and lower glucose (Gl). Treadle-snares were also associated with higher chloride (Cl), haemoglobin (Hb) and packed cell volume (PCV) than cage trapping and netting. Treadle-snares produced indicators of possible muscle damage, exertion and dehydration compared to cage and VSC traps. Cage trapping and netting produced lower indications of exertion, possible muscle damage and dehydration compared to both treadle-snares and VSC traps. These data do not support previous conclusions that due to similar injury scores, treadle-snares and VSC traps produced equivalent welfare outcomes. In restraining traps, injury and death sustained during capture are end-points of poor trapping welfare. Monitoring stress using physiological indicators allows the comparison of the relative potential for different capture techniques to cause pathological and pre-pathological states. As the response of physiological indicators to stress is not independent of time, accurate data on the duration of captivity and the relative intensity of struggling behaviour should be routinely collected when assessing the comparative humaneness of different trap devices.