Rectal pentobarbital as a stress‐free euthanasia method

IN response to the letter by Duncan Mitchell and reply from Aneesa Malik about the cloacal application of pentobarbital for euthanasia of pigeons (VR, 1/8 November 2025, vol 197, pp 380–381) I would like to share my experience with using this method in goats, dogs, cats and wildlife (birds, foxes, rabbits, etc) for many years. My first use of rectal pentobarbitone in goats was not for euthanasia but for the control of life-threatening seizures caused by Cowdria ruminantium (heartwater, a common disease in Mozambique). It was after a suggestion from a local paediatrician, who used rectal pentobarbitone to control seizures in babies with cerebral malaria, in order to be able to place an intravenous cannula. Status epilepticus or prolonged seizuring can cause death from ‘coning’, pressing the brain into the base of the skull. Having experienced this as a very effective and gentle method, I used it later in the UK to euthanase birds (in the cloaca as described by Mitchell), and then in cases of severely emaciated and dehydrated old cats, cats or dogs in severe respiratory distress, or otherwise animals for which the placement of a catheter under restraint would be a stressful experience in the last minutes before their death. If this sounds as if I do this routinely, that is of course not the case. These are exceptional situations. But I have never experienced any reaction of pain or discomfort on application of pentobarbital using a piece of dripline on a syringe and a generous amount of Vaseline. The animals lose consciousness gradually and gently within a few minutes, after which you can either still attempt to inject intravenously, or wait another 10 to 15 minutes when the heart slows down and stops. I consider this as an off-licence use of pentobarbital which can only be justified if the alternative would cause unnecessary distress.