Comparison of frontal-sinus and poll shot locations as secondary methods for euthanizing dairy cattle with a penetrating captive bolt gun

Humane euthanasia is a crucial component of dairy farm animal welfare programs. When using either a gunshot or captive bolt, the frontal-sinus area is well established as the primary shot location, but a secondary shot is often used as well. The objective of this study was to evaluate the efficacy of 2 different secondary shot locations. Cattle from a commercial dairy operation (n = 44) were randomly assigned to receive a secondary shot in the frontal-sinus or poll location and clinical signs of consciousness were assessed. A subsample of adult cattle heads (n = 6) were also evaluated to assess the extent of trauma. With the exception of heartbeat, all signs of sensibility were absent immediately following the first frontal-sinus shot and remained absent until confirmation of death, regardless of treatment (P > 0.05). Relatively fewer animals shot in the poll location had a heartbeat 5 min after being shot (P = 0.03). Pathology results on the subsample of adult cattle showed poll shots rarely penetrated beyond the cerebrum and only 1 of 6 animals had a severed brainstem. We conclude the frontal-sinus and poll locations are similarly effective secondary shot locations, and brainstem damage may not be necessary for irreversible insensibility and death.