MANAGEMENT COMPONENTS

SECTION 8. EUTHANASIA OF ANIMALS ON THE DAIRY

Occasionally it is necessary to euthanize a dairy animal due to fractures, calving complications, severe illness, or natural disasters. Under these conditions, the objective is to provide a swift and humane death, thus quickly relieving the pain and suffering of the animal. Euthanasia is the act of inducing humane death in an animal. The procedure should be done in a manner which will minimize any stress and anxiety experienced by the animal prior to unconsciousness. Stress can be minimized by proper technical proficiency of the person performing the euthanasia. Correctly done, euthanasia will minimize pain and distress in animals, assure safety of the personnel, and protect other animals and people.

When an animal is euthanized, the first step is to produce rapid unconsciousness. This is followed by respiratory and/or cardiac arrest, and ultimately the total loss of brain function. Several common methods of euthanasia are utilized on the dairy. Chemical euthanasia using injectable barbiturate may be offered by veterinarians, while the physical methods of gunshot and penetrating captive bolt gun may be performed by trained personnel.

CHEMICAL METHODS

Acceptable chemical euthanasia methods involve the intravenous injection of barbituric acid derivatives which depress the central nervous system leading to unconsciousness, respiratory and/or cardiac arrest. Only licensed veterinarians have access to barbiturate products; thus this method may have limitations in some situations. Animals euthanized by barbiturate injection should not be used for human consumption or fed to other animals, such as farm cats and dogs.

PHYSICAL METHODS

Gunshot is a physical method that is inexpensive and does not require human contact with the animal. There is potential for ricochet, so strict firearm safety must be observed. Also, local laws and ordinances may prohibit the discharge of a firearm. A .22 is sufficient for most cattle; however, large bulls require at least a .22 magnum or 9 mm round. The use of hollow-point or soft-nose bullets are recommended to increase tissue destruction and decrease ricochet. The muzzle of the firearm should be held 2 to 10 inches from the intended point of contact. The bullet should penetrate the skull at the intersection of two imaginary lines drawn from the inside corner of the eye to a point on the top of the opposite ear (or base of opposite horn). Note, this is not centered between the eyes.

Penetrating captive bolt also kills by concussion and physical destruction of the brain. Adequate restraint is necessary to properly place the gun firmly against the animal's head at the point of impact. The bolt should enter at the same location as described for gunshot euthanasia. It is important to follow the manufacturer's recommendations on the selection of the cartridge strength appropriate for the size of the animal.

Non-penetrating captive bolt guns will stun and not kill the animal. This method must be followed by exsanguination (or another method) to assure rapid death while the animal is unconscious.

After the initial discharge of the gunshot or captive bolt gun, the animal should be exsanguinated (rapid blood loss) to ensure a swift death. To produce rapid bleed out, large blood vessels such as the carotid arteries and/or jugular veins are severed with a sharp instrument.

MONITORING VITAL SIGNS

Following euthanasia procedures, the animal will collapse and may experience a short period (less than 20 seconds) of intense muscle contraction. Poorly coordinated kicking or paddling movements and a period of relaxation will follow, and the pupils of the eyes should be fully dilated. It is important to confirm that the animal is dead y examining the vital signs of life. Death is confirmed by the lack of rhythmic breathing, heartbeat, and corneal reflex. Corneal reflex can be observed by touching the surface of the eye; no blinking or eye movement should occur. An additional euthanasia procedure may be required if there is evidence of any vital signs.