Description and justification of a consistent technique for euthanasia of bovines using firearm and penetrating captive bolt

Firearms and penetrating captive-bolt devices are commonly used to euthanize cattle of all ages, and result in rapid unconsciousness and death due to lethal brain damage when properly conducted. Several reports have described methods to determine the appropriate point of entry when using firearms or penetrating captive bolts for bovine euthanasia. However, some previously described techniques to determine the point of entry may be difficult to remember, necessitate multiple steps to ascertain the point of entry, require adjustment based on breed type, and/or may be challenging in polled cattle if the suggested protocol uses horn anatomy as part of the guidance. A simple, reliable description for an appropriate point of entry and trajectory course for a firearm or captive bolt is to direct the trajectory perpendicular or slightly downward to the frontal sinus plane on midline between the base of the ears at the level of the external acoustic meatus. The orientation of the brainstem and ear is not altered by variables considered in some other protocols. The objective of this report is to describe and justify an uncomplicated, repeatable protocol to consistently determine an appropriate point of entry and line of trajectory for firearm or penetrating captive-bolt euthanasia of domestic bovines across a variety of breeds, ages, skull types, and polled or horned cattle, thus increasing the likelihood that the procedure will be conducted quickly and humanely with minimal stress to the handler and the animal.