Euthanasia of Cattle

Eu•tha•na•sia: “...the act or practice of killing or permitting the death of hopelessly sick or injured...animals...in a relatively painless way for reasons of mercy...” Miriam-Webster Online (www.m-w.com)

There are times when livestock owners, herd managers, or other persons involved with livestock must deal with injured, severely diseased or debilitated cattle. When the decision has been made to stop treating an animal because of a poor prognosis or a questionable economic ‘payback’, or when an animal’s pain and discomfort cannot be reduced to a minimum acceptable level, euthanasia should be administered as soon as possible. It is not an acceptable animal husbandry practice to leave animals to suffer slowly through a prolonged death. Animal welfare guidelines and farm audit programs being implemented by the food industry (e.g. National Council of Chain Restaurants and Food Marketing Institute) consider proper handling and euthanasia of sick and debilitated animals a high priority.

Cattle producers and veterinarians should challenge each other to consider using euthanasia more routinely when it is warranted, especially since it can be administered relatively easily and quickly. Veterinarians have access to ‘medical means’ of euthanizing cattle, and although this method may be more expensive than the other options available, it provides for effective and aesthetically acceptable results in a very safe manner. However, there are times when an animal should be humanely euthanized that a veterinarian is not present or is not immediately available. In these situations, the person responsible for the animal should be able to administer euthanasia in a humane, effective manner.

There are basically 2 acceptable methods for humanely euthanizing livestock that do not involve injecting lethal drugs and these are by means of a gunshot or the use of a penetrating captive bolt (followed by exsanguination or “bleeding out”). These methods can be learned and administered with minimal training. Care must be taken to abide by all legal regulations when purchasing, carrying, or discharging firearms.

The decision to euthanize an animal does not negate the need to handle it in a humane manner until such a time as it is euthanized. For example, it is indefensible from an animal husbandry point of view to drag a down animal across the ground while still alive, or to leave it in an unacceptable environment (e.g. direct sunlight in the heat of the summer).

Using a gun to euthanize an animal can be a humane and inexpensive method if proper guidelines are followed. A firearm that provides sufficient velocity to a bullet of adequate caliber can penetrate the brain and quickly cause massive destruction of brain tissue resulting in an immediate loss of consciousness, followed by the death of the animal. One of the other advantages of using a gun to administer euthanasia is that direct contact with the animal is not required - in fact, it is strongly suggested that the end of the firearm be held a few inches away from the appropriate target site.

However, use of a gun also poses certain challenges, the most significant one being the potential for a bullet to ricochet instead of penetrating the skull. Obviously this could be very dangerous for nearby people and animals so proper precautions must be taken!

A pistol or rifle firing .22 caliber bullets (including hollow or soft point) can be used to humanely euthanize young cattle, but these may not consistently penetrate the skull of adult cows and bulls. Although a .22 caliber solid point bullet may be sufficient, it is recommended that .357 caliber or 9 mm bullets be used on large adult cows and bulls in order to produce consistently acceptable results.

Penetrating captive bolt pistols penetrate the skull, causing trauma and concussive forces to the brain. Although the destruction of brain tissue is not usually as extensive as is seen with a properly placed gunshot, the animal should immediately become unconscious. In order to ensure the death of the animal it should be exsanguinated (bled out) as soon as it is unconscious - some animals may recover consciousness if this is not done. Although this part of the procedure is messy it is important that it is carried out promptly and properly. The easiest method in cattle is to sever the jugular vein and carotid artery close to the base of the jaw, using a long-bladed knife. The point of the (sharp!) knife should be stabbed through the skin just below the cervical spine and deep into the tissues, almost (or through) the skin on the other side, and then pulled down/forward to sever the trachea and vessels. This should result in a
substantial flow of blood, with the death of the animal following in minutes.

Generally, a captive bolt pistol is safer to use than a gun since there is no ‘loose projectile’ involved - although direct contact must be made between the pistol and the animal’s skull.

While there is an initial purchase cost involved - as there would be with a firearm - ongoing operational costs of a captive bolt pistol are very reasonable.

(Non-penetrating captive bolt pistols do not cause enough consistent trauma to the brain of livestock and should therefore be avoided.)

Location, location, location! With either the gunshot or penetrating captive bolt method of euthanasia it is very important that the correct location is chosen as the point of entry for the projectile in order for the technique to be effective. For cattle the correct location is on the ‘forehead’ at the intersection of two lines drawn from the medial canthus (inside corner) of the eye to the base of the opposite horn (or slightly above the ear in polled animals, where the horn would have been!). The bullet or penetrating bolt should enter at right angles to the skull to minimize the possibility of ricocheting and to maximize the destruction of brain tissue.

The final step in euthanizing an animal is to ensure that it is dead. The lack of a pulse is not enough to confirm death, and respiration may be very slow and/or shallow in an unconscious but not yet dead animal. Instead, the corneal reflex should be evaluated by touching the surface of the eyeball and watching for a reaction, or a stethoscope used to listen for a heartbeat. In any case, the animal should be rechecked once or twice after several minutes or hours to ensure that it is truly dead.

(Personnel who euthanize animals should be monitored carefully for their attitude and level of comfort with carrying out the procedure, since they may begin to develop a careless or callous attitude toward animals, or experience emotional discomfort. In these situations it is important to provide appropriate support for the affected person and to delegate euthanasia responsibilities to another person.)

The impact on other farm employees, neighbors and farm visitors should not be overlooked. Involuntary musculoskeletal movements or vocalization may occur, even when the brain tissue has been sufficiently destroyed to render the animal completely unconscious, and this could give the impression that the technique is being inappropriately carried out. Exsanguination, although painless to the unconscious animal, may be unpleasant for some people to observe. Therefore, it is advisable that only people who are required for carrying out the procedure be present.

There are effective and inexpensive methods available to non-veterinarians which permit the humane euthanasia of cattle. Veterinarians and cattle producers should discuss implementing protocols for determining when and how to euthanize animals to minimize suffering, to improve animal welfare standards and to reduce economic losses.

For further information on humane euthanasia of cattle, including images of appropriate technique, please see the following web resource: http://www.vetmed.ufl.edu/lacs/HumaneEuthanasia.htm

Ernest Hovingh, Veterinary Science Extension