Euthanasia in Horses
Dr. Philip Johnson
It is not recommended that you observe the euthanasia of horses because the sight of the procedure is inevitably distressing. Generally, horses are euthanized using one of two methods. Intravenous overdose injection of an anesthetic agent, typically a barbiturate. This is the most common method today and is quite humane when performed with care. Some veterinarians choose to give a sedative first to quiet the horse for the final injection and in many cases reduces the speed at which the horse hits the ground in many cases. The barbiturate anesthetic goes to the brain immediately and induces a state of sleep, usually within 30 seconds or less. Then within seconds the horse will also become paralyzed and go down. Sometimes a horse will slip gently first to its knees, but at other times the animal will fall dramatically to the side. The veterinarian or handler's job is to prevent the horse's head from crashing to the ground, but this cannot always be avoided when human safety is on the line. Regardless, the horse will feel nothing either way.
After the horse goes down, your veterinarian will check the heart to make sure the horse is dead before proceeding. There may be some twitching, and even a few breaths before the horse is still, but these are usually minimal and have nothing to do with the presence of life. The presence of a barbiturate in the horse's system will have no bearing on the accuracy of an autopsy but will require that the carcass be incinerated or buried, because the injected drugs render the horse's tissues unsuitable for consumption by other animals.
Gunshot to the head. This method is a time-honored method. In the hands of a skilled veterinarian, a gunshot to the head is a very humane, in that it is instantaneous and painless. It is also an inexpensive method for euthanasia. However, if the horse is to have a proper autopsy, including the brain (for example in a horse suspected of rabies), this is not an acceptable method.
Care of the Remains
If you decide on euthanasia, you will have to determine what will be done with the body. Certainly, whenever there is any doubt regarding the cause of the horse's medical problem, a post-mortem examination should be considered. In the face of toxicological diseases and some infectious diseases, other horses may be at risk and a post-mortem examination will assist in determining the likely cause. Furthermore, if the possibility that human contacts could have been exposed to a zoonotic disease (one that affects animals and human beings) such as rabies, a post-mortem examination is mandatory. The post-mortem examination may be undertaken locally by the attending veterinarian or the body may be transported to a veterinary pathology facility.
Alternatively, the horse's body may be buried on the farm premises, submitted to a horse renderer ("knacker") for processing, incinerated (if local facilities are available), donated to local hunt kennels, or donated to a college of veterinary medicine to help with the teaching of horse anatomy. The horse renderer is often willing to collect the body and might also pay a small fee to offset the cost of euthanasia.
Entrusting Your Horse
If you leave the care of your horse in someone else's hands, decisions pertaining to the need for euthanasia should be reviewed ahead of time, or at least contact information should be provided for the care-giver. In the event that you cannot be contacted in the event of a medical emergency, the caregiver should know ahead of time how you would wish to proceed. These decisions should be reviewed with the surrogate/handler and the local veterinarian and written records of your wishes should be maintained.