Sally - a captive bolt is just that, the 'charge' goes behind the bolt - there used to be ones that penetrate, but they were considered a disease risk and now they deliver a blow to the skull without penetrating - basically its a bit like being hit over the head with a hammer. Given that this might not kill an animal, it is best to bleed it. You'd do that after 'normal' slaughter anyway...
That's pretty much what I had understood, which is why I asked fmsnutter for more info as her post suggested to me that she euthanased by captive bolt gun only
As a vet, I try to offer the option of euthanasia of sheep/cattle/horses by injection or by captive bolt gun.
Some people (myself included) often prefer the gun as it suddenly renders the animal unconscious with no further suffering.
Others absolutely prefer an injection.
Hi Sally
*WARNING, DON'T READ IF OF SENSITIVE DISPOSITION, GRAPHIC DETAIL OF CAPTIVE BOLT EUTHANASIA*
There are different types of captive bolt available, as described, there is a version that doesn't penetrate the head, causing stunning by concussion, which I believe can be used for Halal slaughter, as they are not allowed to eat meat unless it has been 'killed' by cutting its throat, whereas in the UK animals must be rendered unconscious first, so this type satisfies both the laws of the UK, stunning the animal, and Halal tradition whereby the animal will still be alive when bleeding.
The kind we have (and I have also seen used in abattoirs) has a cartridge behind a 'bolt' which when shot, protrudes out of the gun by a short distance, enough to penetrate the skull and brain, causing immediate unconsciousness in the animal. On occasion, this bolt will cause sufficient damage to the brain to kill, but the only way to be sure the animal is dead is to ensure brainstem death. In the abattoir, this is done by bleeding, or this could be done for euthanasia as well.
In practice when euthanising an animal, not for human consumption, it is usually done by a procedure called 'pithing', where a long pole, either metal or plastic, is put into the hole to ensure the brainstem has been destroyed. This cannot be done when the animal is intended for human consumption due to concerns over BSE, etc.
I have also used the captive bolt to render a horse unconscious instantly, followed by a lethal injection, as it was in the field in the dark, and I couldn't be sure the captive bolt and pith had done the job, and certainly did not want the scenario you painted where the horse could wake up.
Using a captive bolt, after a very short period of time, it is possible to be sure that the animal has died, as the stun from the captive bolt will wear off within a minute, and therefore after that point, if it is not breathing, it will not wake up. Whereas, I have heard horror stories from other vets about lethal injection in sheep, where heart and breathing have stopped, but 10 minutes later it has woken up. This is why I would always give a very high dose of injection (like the 2 bottles for an alpaca story), as it is not possible to break down the injection and come round from a greater dose, and make sure that it won't wake up again by waiting a suitable length of time.
Hope that clears it up, and wasn't too gory reading
Suzanne