Euthanasia of Horses
Table of Contents
One always hopes that an older horse, that has been a friend for a long time, will quietly slip away (die) peacefully in the night. However, this is not always the case. As guardians of our animals, we have to be prepared for one of the hardest things we have to think about, the putting to sleep or euthanasia of our horse.
The word 'euthanasia' is derived from 'eu' - meaning good, and 'thanatos' - meaning death. A good death would be one that occurs with a minimum of pain and at an appropriate time in the horse's life to prevent pain and suffering (1). The difficult part is deciding 'when is the right time?' Whenever possible, owners should consult with their veterinarian.
A number of reasons are mentioned when considering euthanasia, including: for humane reasons, to prevent suffering caused by a medical condition, an injury (e.g., fractured leg), or disease, such as severe heaves or incurable colic. Age is often mentioned, but how old is old? The oldest horse known in Ontario was 48 when it died. On occasion, convenience is cited as the reason for euthanasia. The owner no longer needs or wants the horse and they don't want it to go to another owner.
The American Association of Equine Practitioners provides some guidelines to the question 'When is the right time?' The following criteria may be helpful:
Before reaching a final decision, consult with your veterinarian and your insurance agent. Many companies providing insurance coverage for a horse will require notification and, perhaps, a second opinion before honouring a policy.
When these criteria are not met, there may be other reasonable options to consider. Will changing the way the horse is managed improve the horse's quality of life? Moving a horse with heaves to a place that has 24-hour-a-day, 7-day-a-week outdoor housing can make a horse with severe heaves almost normal again. Well mannered horses, which are lame with mild navicular disease, may not be able to campaign in shows. However, they may be suitable as lead horses in a riding-for-the-disabled program if their condition can be controlled with medication and/or farrier care. Talk to your veterinarian about the possibility of these opportunities in your area.
Horses should be euthanized in a location that is easily accessible for removal and disposal. Avoid unnecessary pain or suffering when moving injured animals.
It is hard enough to decide that it is time to euthanize your horse. It is even harder to complete the task yourself. Therefore, prior to the need arising, speak with your veterinarian and consider the various options. They include:
A veterinarian will often administer an intravenous injection of a tranquilizer, followed by an overdose of a barbiturate. This is a very fast and pain-free method of euthanasia. It is usually less traumatic emotionally to the owner than other methods. However, the euthanized horse now contains significant levels of barbiturate. The carcass must not be scavenged prior to disposal. It is your responsibility to ensure that birds, wolves and dogs do not eat from a contaminated carcass. There are sufficient drugs in a euthanized horse to be a danger to a scavenger's health.
Lethal injection may not be feasible in some areas since a veterinarian may not always be available for an emergency euthanasia. When scheduling a veterinary-assisted euthanasia, ensure that you schedule your veterinarian as well as a backhoe operator, or other means of disposal, on the same day.
The use of a firearm is a very efficient method of euthanizing a horse, when administered by an experienced person. The weapon should be fired with the muzzle close to the head (but not against the skull) at the correct location and in the required direction to ensure that the shot penetrates the brain and does significant damage (2). It is essential that the horse is properly restrained. Muscle twitching may still occur even though the shot has been lethal. A number of calibers can be used, including: a rifled slug fired by a shotgun (410 gauge or larger) and rifles (including .308 and .223), when placed 1-2 inches from the skull. The smaller caliber .38 police service revolver or .22 calibre long rifle may render the horse unconscious but may not be lethal and may require exsanguination (bleeding out) subsequent to shooting.
While being fast and readily available in most rural communities, aesthetically, the use of a firearm may be unpleasant to the owner. In addition, the release of a projectile(s) by a rifle or shotgun poses a potential danger to animals and humans in the vicinity.
Location and direction of gunshot
A captive bolt pistol discharges a blank rifle cartridge (no bullet). It drives a piston-like bolt forward. When placed on the skull of an animal, the bolt is projected forward and delivers a lethal blow to the brain. The location on the skull and angle of the bolt is the same as recommended for euthanasia by a firearm.
A captive bolt pistol should only be used by an experienced operator. It does have the advantage that no permits or licences are required and it can be legally transported in a vehicle. For safety reasons, the captive bolt should only be used in a location, such as a knocking box, which provides protection from a horse falling on the operator.
Owners can transport their horse to a licensed horse abattoir, where experienced personnel can humanely euthanize it. Aesthetically, however, this may not be pleasant for the owner of a horse. This is a viable option only in those areas where horse abattoirs exist.
Horses that are not able to rise and stand unassisted may not be loaded, transported, and/or unloaded at an abattoir. These animals may only be loaded with veterinary authority for treatment purposes (3).
In areas where veterinary schools are close at hand, horses can be donated to the teaching facility. Horses will be examined and humanely treated while in the care of the teaching hospitals. Subsequently, they will be euthanized using an overdose of a barbiturate.
Confirm that the horse is dead within one minute of euthanasia and again at five minutes, or more. This can be achieved by monitoring the heart rate and, subsequently, the corneal reflex. The pupils of the eyes should be dilated. A blinking response to touching the cornea of the eye indicates brain activity and will necessitate the application of an alternate euthanasia method.
In Ontario, on-farm management and disposal of deadstock is covered under the Nutrient Management Act (NMA). Owners are required to properly dispose of mortalities in a safe, environmentally friendly manner within 48 hours of its death. When euthanizing an animal, it is a good idea to choose a location where you can easily reach the euthanized animal and quickly dispose of it. It is important to remember that, regardless of which disposal option is chosen, dead animals should be kept away from wells and surface water.
Acceptable means of on-farm disposal under the NMA include burial, incineration, composting, disposal vessels, or anaerobic digestion. Owners may also take deadstock to:
Scavenging must be prevented at all times. If mortalities are not disposed of or stored properly, wild animals, dogs, or birds could exhume them and help spread diseases. Partially decayed mortalities are odorous, unsightly, attract rodents and are a breeding spot for flies.
If an owner chooses to bury, incinerate or compost, the regulation establishes requirements to minimize impacts on the environment.
The standards for burial pits have been expanded in order to protect ground and surface water and prevent scavenging. The deadstock in a burial pit must be covered by at least 0.6 m of soil at all times, and pits must be monitored regularly for a year for signs of depression in the soil surface. Depressions may result in the collection of water in the pit, slowing decomposition and increasing the risk of runoff.
Burial pits may not exceed 2500 kg of deadstock weight per pit. This may pose challenges for producers that, unfortunately, have multiple mortalities at the farm. Multiple burial pits may be established on the same site, provided there is adequate separation distance between them to reduce the risk of groundwater contamination through leaching.
Areas of the province where bedrock, surface water or groundwater is close to the surface are unsuitable. Burial of mortalities in areas susceptible to ground water contamination could result in adverse effects in nearby wells. The potential for ground water contamination and subsequent well-water contamination is a function of the soil type, bedrock depth, and ground water depth. Coarse soils (sands and gravel) may increase ground water contamination risks because they allow rapid movement of liquids away from the burial site with minimal filtration or treatment. Shallow bedrock is a concern since open fractures in bedrock permit rapid movement of contaminated water with minimal filtration or treatment.
Winter conditions with frozen soils can make the burial option difficult.
On-farm composting of a carcass is readily available but not aesthetically acceptable to everyone. It does, however, offer an option for immediate disposal of livestock mortalities of all sizes, as well as afterbirths, which can generally be done year round (6).
On-farm composting can provide an excellent source of organic matter and nutrients to farms. Done properly, composting will kill pathogens and stabilize the organic and nutrient content of the finished compost. If done improperly, composting may result in odours, scavenging, and potential environmental impacts.
The availability and price of substrate for carcasses to be placed in may impact on the choice to compost deadstock. Only the following substrates may be used:
The volume and size of the deadstock to be composted will impact on the location of the compost pile. The larger the deadstock, the longer it will take to compost fully, so dedicated areas should be established for composting. The piles must not be more than 600 m2 in area, and each pile should not contain more than 600 m3 of deadstock and substrate. Multiple piles can be established with appropriate setbacks between them to reduce the cumulative impact of leaching.
Composting is considered complete when there is no soft animal tissue, no bone fragments larger than 15 cm and no other animal matter larger than 25 mm, and no offensive odours.
While the on-farm incineration of horses is permitted in Ontario, there are certain factors that must be taken into account.
Incinerators used for deadstock disposal must have a Verification Certificate issued by ETV Canada, certifying that it can meet operating temperatures in the secondary chamber. High temperatures in the secondary chamber will decrease the contaminants in the emissions. They are generally designed for the disposal of consistent volumes of smaller animals. Larger animals would have to be processed before using an incinerator.
The cost of a commercial unit is generally not justifiable for occasional deadstock disposal.
Disposal vessels were developed in response to predation problems on sheep farms. They are an inexpensive and non-labour intensive method of disposing of smaller-sized deadstock, placentas and aborted feti.
A leakproof and impervious container is located on the ground surface, partially buried or fully buried in the ground. A hatch is positioned on the vessel in such a way that deadstock can easily be deposited into the vessel. A vent or duct allows insects to enter for the purposes of aiding decomposition, while restricting access to scavengers.
Depending on how big the vessel is, how much deadstock is put into it, and the rate of filling, the vessel could be sufficient to allow for decomposition over many years. When the operator wishes to stop using the vessel, or the vessel is full, the vessel is filled with soil, and the hatch is locked.
Disposal vessels are useful for farms where small, or inconsistent volumes of deadstock are generated.
Farmers may also choose to put deadstock into their anaerobic digesters or take them to an off-site digester. Deadstock would need to be processed in such a way that the particle size is appropriate for the facility to handle. There will likely be tipping charges for off-site facilities, so the cost of transport and tipping should be compared to the costs of other disposal options.
Deadstock may be picked up on the farm, delivered to the collector, or to a common bin, where deadstock from multiple farms is stored temporarily for pickup. Common bins can increase the efficiency of collection services.
Deadstock awaiting pick-up must be stored so that it is concealed from public view, and that any liquids from the animal are prevented from escaping onto the ground. Not only does improper storage of deadstock result in complaints from the public, it may attract scavengers and predators and pose biosecurity problems for the farm.
There are areas of the province where no collection service is offered, and there are some species of livestock that are not picked up. The costs of collection should be compared to the operational and management costs of disposal on-farm.
Where an owner transports their own deadstock, the deadstock must be kept out of public view at all times. The vehicle or container must be constructed to prevent the spillage of liquids, and of materials that may be cleaned and disinfected after transport.
Dragging a dead animal into the bush and leaving it to be scavenged is illegal in Ontario and, therefore, not an option.
Many of the difficult decisions associated with the euthanasia of a horse can be made prior to the event. The development of a euthanasia plan with your veterinarian will ensure your wishes will be honoured in the event you or your veterinarian are absent in the case of an emergency.
Euthanasia plans outline the preferred method to be used, alternate methods, options for carcass disposal, and contact information for veterinarians. The euthanasia plan should be dated and posted in a central place in the stable. All employees should be aware of the plan. The following is an example of a euthanasia plan (7).
Emergency Euthanasia Action Plan
The feeling of sadness over the death of a horse is normal. Grief can leave you feeling sad, angry or guilty, and alone. The expression of our emotions is part of the healing process. For those who feel a need to express their emotions, the Ontario Veterinary College (OVC) provides a Pet Loss Support Hotline. It is staffed by a group of veterinary students who are trained to listen and support you through your grief. It provides a non-judgmental forum where you can express your feelings and concerns surrounding the loss of your animal. For further information, please refer to the OVC Pet Loss Support Hotline or call (519) 824-4120, extension 53694.
For more information:
Toll Free: 1-877-424-1300