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Gunshot or Penetrating Captive Bolt

Properly applied, euthanasia by either gunshot or penetrating captive bolt (combined with procedures to ensure death), causes less fear and anxiety and induces a more rapid, painless, and humane death than can be achieved by most other methods. However, both methods may involve human risk, and therefore, require skill and experience. Neither method should be attempted by untrained or inexperienced persons.

Gunshot

In most circumstances on the farm or ranch, gunshot is the only practical method of euthanasia. This procedure requires the selection of an appropriate firearm and bullet with sufficient velocity, energy and size to pass through the skull (enter the brain), and cause massive brain destruction. A .22 caliber long rifle solid point bullet fired from either a pistol or rifle is sufficient for young animals. Hollow or soft point .22 caliber bullets increase brain tissue destruction, but may not penetrate the skull in adult animals and are therefore, not recommended. Euthanasia of bulls and some adult cows, horses, or cervids (elk) by gunshot requires larger caliber firearms, because of thickness of the skull. Proper placement of the bullet is essential and best achieved by holding the firearm within 2 to 3 feet (60 to 90 cm) when possible of the intended target. The muzzle of the firearm should not be held or placed against the head.

Shotguns are an excellent alternative to rifles or handguns for conducting euthanasia procedures. As with rifles and handguns, they must be used at close range, preferably within 1 to 2 yards (1 to 2 meters) of the intended target. Options for mature cattle (including bulls), horses and elk include the 12, 16 and 20 gauge shotgun loaded with slugs or No. 2, 4, or 6 size birdshot. The .410 and 28 gauge shotguns should not be used on larger animals, particularly bulls.

  • Advantages: When properly positioned a bullet, birdshot from a shotshell or a slug will cause massive brain destruction and immediate unconsciousness. Gunshot is inexpensive and does not require close contact with the animal.
  • Disadvantages: Gunshot may be dangerous. When using a rifle or handgun, ricochet of the bullet is possible and therefore, the operator and bystanders must use extreme care in positioning of themselves and others when the procedure is performed. Another disadvantage is, that in cases involving fractious animals, it may be difficult to get close enough to accurately hit the vital target area.

Whereas most animals for which euthanasia by gunshot is indicated are either debilitated or down, opportunity for proper placement of the bullet is less difficult. On the other hand, for animals on their feet and mobile or potentially dangerous, it may be necessary to shoot from a distance. In such cases, the preferred target areas are the head, neck, or lower thorax just behind the elbow.

Penetrating Captive Bolt

Penetrating captive bolt followed by immediate exsanguination (bleeding out) is the preferred method for euthanasia of cattle in abattoirs (slaughter facilities). The mode of action of a penetrating captive bolt gun is concussion and trauma to the brain. This requires that it be held firmly against the surface of the head over the intended site. This constitutes a major difference between the placement of a firearm and the placement of a penetrating captive bolt. Because placement and positioning of the projectile is critical, some degree of restraint is required for proper use of this device.  A rope halter is sufficient to restrain the head for ensuring proper placement of the penetrating captive bolt.

There are two types of captive bolt: penetrating and non-penetrating. Both are discharged by gunpowder or compressed air. A penetrating captive bolt works by concussion and trauma to the brain. It causes immediate unconsciousness and destruction of brain tissue as a result of penetration of the discharged bolt. While the destruction of brain tissue with the penetrating captive bolt may be sufficient to result in death, operators are strongly advised to ensure death by exsanguination, pithing or the injection of a chemical substance such as KCl to ensure death. The non-penetrating captive bolt device works by concussion and only stuns the animal. Since the destruction of brain tissue is minimal and level of consciousness more variable, it should not be used alone for euthanasia of livestock in field situations.

  • Advantages: Although not without risk, penetrating captive bolt is generally safer for the operator and bystanders. Beyond the initial investment of a penetrating captive bolt, continued use is inexpensive.
  • Disadvantages: Death may not occur unless followed by exsanguination, pithing or the intravenous injection of a saturated solution of approximately 120 ml of KCl. The operator must be close to the animal and have it adequately restrained in order to get proper placement of the penetrating captive bolt. The penetrating captive bolt should not be fired when the animal is moving its head.

Anatomic Landmarks

In cattle, the point of entry of the projectile should be at the intersection of two lines each drawn from the rear corner (outside corner) of the eye to the base of the opposite horn.

Gunshot or Penetrating Captive Bolt | Iowa State University

Special Considerations: Euthanasia of Bulls

Bulls pose unique challenges due to:

  • Larger body mass,
  • Aggressive behavior,
  • Thicker cranial structures.

Recommendations:

  • Use high-caliber firearms, heavy-duty captive bolt devices, or large-gauge shotguns.
  • Restraint is typically required but should be minimized in duration.
  • Prepare euthanasia equipment in advance to reduce stress during restraint.

Penetrating captive bolt or gunshot followed by immediate exsanguination are the preferred methods of euthanasia in sheep. For hornless sheep, goats and rams the recommended sites for placement of the gun or penetrating captive bolt include the top of the head or slightly behind the poll. Sheep should be exsanguinated, pithed or given KCl by intravenous injection within 10 seconds after stunning by penetrating captive bolt or they may regain consciousness. Exsanguination, pithing and intravenous injection techniques of cattle and sheep should be performed as described on Exsanguination section.

In horned sheep and rams the top of the head may not be the ideal location because of the thickness of the skull in this region. Instead, an alternate position and orientation for penetrating captive bolt or gunshot in horned animals is on a line from the poll and aimed downward toward the back of the throat.  An alternative position for placement of the penetrating captive bolt or firearm in horned animals is the front of the skull directing the bolt or bullet toward the spinal cord.

The site for penetrating captive bolt or gunshot placement in horned goats is similar to that described for horned sheep and rams.  An alternate site is slightly behind the poll aimed toward the lower part of the chin.

Anatomical Landmarks | Iowa State UniversityAnatomical Landmarks | Iowa State University

For llamas, the proper site is similar to that of hornless sheep.

Anatomical Landmarks | Iowa State University

For swine, there are three possible sites: frontal, temporal and from behind the ear toward the opposite eye. Recommended placement of the penetrating captive bolt or gun for use of the frontal site is in the center of the forehead slightly above a line drawn between the eyes. The bolt or free bullet should be directed toward the spinal canal. Proper placement and aim of the euthanasia device is particularly important since the brain is relatively small and well protected by sinuses. Alternative sites for gunshot (only) are the temporal region or from behind the ear directed diagonally toward the opposite eye. As advised anytime euthanasia is performed with a firearm, one must be careful of the location of on-lookers. By-standers should always be positioned behind the shooter.

Anatomical Landmarks | Iowa State University

Horses may be euthanized by gunshot or penetrating captive bolt. As described previously, use of the captive bolt requires good restraint so that the device may be held in close contact with the skull when fired. The site for entry of the projectile is described as being on the intersection of two diagonal lines each running from the outer corner of the eye to the top of the opposite ear (note diagram).  An alternative means of finding the appropriate site is to direct the bolt or free bullet 1-2 inches (2.5-5 cm) above the intersection of 2 lines each drawn from the top of the eye to the base of the opposite ear.

Emergency Euthanasia Guidelines for Horses

The proper site in deer is similar to that in cattle. The methods described for emergency euthanasia of deer are similar to those described previously for cattle and small ruminants.  Recommended positions and direction for firing of a penetrating captive bolt or gunshot in deer are as shown.

Since deer requiring euthanasia may be encountered on farm or roadside conditions, it is important to consider the natural instincts of fear and anxiety of a farm-raised verses wild animal. Approaching an injured wild deer will likely increase it’s distress causing it to attempt to flee which may only compound its misery. In general, whenever wildlife are involved in highway accidents, the best advice is to contact the appropriate state wildlife authorities. Their personnel are properly trained to handle these emergencies.

Signs of Effective Stunning with a Penetrating Captive Bolt

To confirm that an animal has been properly stunned and rendered unconscious, observe the following:

  • Immediate collapse upon firing
  • No attempts to stand or right itself
  • Instant muscle rigidity followed by involuntary limb movements
  • Cessation of normal rhythmic breathing
  • Eyes remain open, with a fixed, forward gaze

Important: Any vocalization after stunning indicates the animal may be regaining consciousness and requires immediate corrective action.

Common Causes of Ineffective Stunning

Poor performance of captive bolt devices is often due to:

  • Lack of regular cleaning and maintenance
  • Improper storage of cartridges (should be kept cool and dry)
  • Failure to replace worn or damaged parts

Confirmation of Death

Use the following criteria to assess and confirm death:

  • No heartbeat
  • No respiration
  • No corneal reflex
  • Presence of rigor mortis

Step-by-Step Assessment

  1. Check for Heartbeat
    • Use a stethoscope placed just behind the animal’s left elbow.
    • Do not rely on a pulse, as it is often not detectable in these cases.
  2. Observe Respiration
    • Watch for chest movement.
    • Be aware that breathing may be irregular or absent in unconscious animals—interpret with caution.
  3. Test the Corneal Reflex
    • Gently touch the surface of the eye.
    • A conscious animal will blink. Lack of blinking indicates absence of reflex.
  4. Confirm Over Time
    • If unsure, observe the animal for several hours.
    • Continued absence of movement, heartbeat, respiration, and corneal reflex confirms death.

Minimum Time for Confirmation

  • Death should be confirmed only after at least 5 minutes of:
    • No heartbeat
    • No respiration
    • No corneal reflex

Important Notes

  • Always use multiple indicators to confirm death.
  • Document findings clearly in the animal’s record.
  • When in doubt, consult a supervisor or veterinarian.

 

The following is a partial list of methods considered as “unacceptable” for euthanasia of livestock:

  • Manually applied blunt trauma to the head such as a large hammer
  • Injection of any chemical substance not labeled for use as a euthanasia agent
  • Injection of air into a vein
  • Electrocution as with a 120 or 220 volt electrical cord

Laws regarding acceptable methods of euthanasia vary from state to state.  Persons are advised to contact local and/or state legal authorities for further information.  A person convicted of violating these laws may be charged with a felony in some states.