Computed tomographic assessment of brain tissue disruption and skull damage in equine cadaveric heads caused by various firearm-ammunition combinations applied as potential gunshot methods for euthanasia of horses

Jane R. Lund Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706.

Search for other papers by Jane R. Lund in
Current site
Google Scholar
PubMed
Close
 DVM, MS
,
Howard R. Ketover Irongate Equine Clinic, Madison, WI 53719.

Search for other papers by Howard R. Ketover in
Current site
Google Scholar
PubMed
Close
 DVM
,
Scott Hetzel Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53706.

Search for other papers by Scott Hetzel in
Current site
Google Scholar
PubMed
Close
 MS
,
Kenneth Waller Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706.

Search for other papers by Kenneth Waller in
Current site
Google Scholar
PubMed
Close
 DVM, MS
, and
Sabrina H. Brounts Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53706.

Search for other papers by Sabrina H. Brounts in
Current site
Google Scholar
PubMed
Close
 DVM, PhD

Abstract

OBJECTIVE

To evaluate with CT the characteristics of brain tissue disruption and skull damage in cadaveric heads of adult horses caused by each of 6 firearm-ammunition combinations applied at a novel anatomic aiming point.

SAMPLE

53 equine cadaveric heads.

PROCEDURES

Heads placed to simulate that of a standing horse were shot with 1 of 6 firearm-ammunition combinations applied at an aiming point along the external sagittal crest of the head where the 2 temporalis muscles form an inverted V. Firearm-ammunition combinations investigated included a .22-caliber long rifle pistol firing a 40-grain, plated lead, solid-core or hollow-point bullet (HPB); a semiautomatic 9-mm pistol firing a 115-grain, jacketed HPB; a semiautomatic .223-caliber carbine firing a 55-grain, jacketed HPB; a semiautomatic .45-caliber automatic Colt pistol firing a 230-grain, jacketed HPB; and a 12-gauge shotgun firing a 1-oz rifled slug. Additional heads placed in a simulated laterally recumbent position were shot with the semiautomatic 9-mm pistol–HPB combination. All heads underwent CT before and after being shot, and images were evaluated for projectile fragmentation, skull fracture, and cerebrum, cerebellum, and brainstem disruption.

RESULTS

Computed tomography revealed that all firearm-ammunition combinations caused disruption of the cerebrum, cerebellum, and brainstem that appeared sufficient to result in instantaneous death of a live horse. Hollow-point ammunition was as effective as solid-core ammunition with regard to brain tissue disruption. Brain tissue disruption was not affected by head positioning.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the examined firearm-ammunition combinations, when applied at a novel aiming point, appear to be reasonable options for euthanasia of horses.

Abstract

OBJECTIVE

To evaluate with CT the characteristics of brain tissue disruption and skull damage in cadaveric heads of adult horses caused by each of 6 firearm-ammunition combinations applied at a novel anatomic aiming point.

SAMPLE

53 equine cadaveric heads.

PROCEDURES

Heads placed to simulate that of a standing horse were shot with 1 of 6 firearm-ammunition combinations applied at an aiming point along the external sagittal crest of the head where the 2 temporalis muscles form an inverted V. Firearm-ammunition combinations investigated included a .22-caliber long rifle pistol firing a 40-grain, plated lead, solid-core or hollow-point bullet (HPB); a semiautomatic 9-mm pistol firing a 115-grain, jacketed HPB; a semiautomatic .223-caliber carbine firing a 55-grain, jacketed HPB; a semiautomatic .45-caliber automatic Colt pistol firing a 230-grain, jacketed HPB; and a 12-gauge shotgun firing a 1-oz rifled slug. Additional heads placed in a simulated laterally recumbent position were shot with the semiautomatic 9-mm pistol–HPB combination. All heads underwent CT before and after being shot, and images were evaluated for projectile fragmentation, skull fracture, and cerebrum, cerebellum, and brainstem disruption.

RESULTS

Computed tomography revealed that all firearm-ammunition combinations caused disruption of the cerebrum, cerebellum, and brainstem that appeared sufficient to result in instantaneous death of a live horse. Hollow-point ammunition was as effective as solid-core ammunition with regard to brain tissue disruption. Brain tissue disruption was not affected by head positioning.

CONCLUSIONS AND CLINICAL RELEVANCE

Results indicated that the examined firearm-ammunition combinations, when applied at a novel aiming point, appear to be reasonable options for euthanasia of horses.

Contributor Notes

Address correspondence to Dr. Brounts (sabrina.brounts@wisc.edu).
  • 1.

    2 Sec 201 Federal Food, Drug, and Cosmetic Act. Available at: www.govinfo.gov/content/pkg/USCODE-2011-title21/pdf/USCODE-2011-title21-chap9.pdf. Accessed May 23, 2019.

    • Search Google Scholar
    • Export Citation
  • 2.

    US Fish and Wildlife Service Office of Law Enforcement. 16 USC 668–668d Bald and Golden Eagle Protection Act, Subchapter II—Protection of bald and golden eagles. Available at: www.fws.gov/le/USStatutes/BEPA.pdf. Accessed May 23, 2019.

    • Search Google Scholar
    • Export Citation
  • 3.

    Subchapter II—Migratory bird treaty. Available at: www.fws.gov/le/USStatutes/MBTA.pdf. Accessed May 23, 2019.

  • 4.

    Payne J, Farris R, Parker G, et al. Quantification of sodium pentobarbital residues from equine mortality compost piles. J Anim Sci 2015;93:1824 1829.

  • 5.

    Bonhotal J, Schwarz M, Williams C, et al. Horse mortality: carcass disposal alternatives Available at: cwmi.css.cornell.edu. Accessed Feb 27, 2020.

    • Search Google Scholar
    • Export Citation
  • 6.

    Cima G. Pentobarbital in food sickens dogs, food maker wants more regulations. J Am Vet Med Assoc 2017;250:738.

  • 7.

    Leary S, Underwood W, Anthony R, et al. Part II—Methods of euthanasia. In: AVMA guidelines for the euthanasia of animals: 2020 edition;22–48 and 78. Available at: www.avma.org/sites/default/files/2020-01/2020_Euthanasia_Final_1-15-20.pdf.

    • Search Google Scholar
    • Export Citation
  • 8.

    Shearer JK, Nicoletti P. Humane euthanasia of sick, injured, and/or debilitated livestock: procedures for humane euthanasia. Available at: edis.ifas.ufl.edu. Accessed May 25, 2019

    • Search Google Scholar
    • Export Citation
  • 9.

    Baker HJ, Scrimgeour HJ. Evaluation of methods for the euthanasia of cattle in a foreign animal disease outbreak. Can Vet J 1995;36:160 165.

    • Search Google Scholar
    • Export Citation
  • 10.

    Hollerman JJ, Fackler ML, Coidweli DM, et al. Review article gunshot wounds: 1. bullets, ballistics, and mechanisms of injury. Am J Roentgenol 1990;1:685 690.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 11.

    Lindsey D. The idolatry of velocity, or lies, damn lies, and ballistics. J Trauma 1980;20:1068.

  • 12.

    Shrout PE, Fleiss JL. Intraclass correlations: uses in assessing rater reliability. Psychol Bull 1979;86:420 428.

  • 13.

    Holm S. A simple sequentially rejective multiple test procedure. Scand J Stat 1979;6:65.

  • 14.

    Farm animal care council for the care and handling of equine codes of practice. Ottawa, Canada: Equine Canada and the National Farm Animal Care Council. 2013. Available at: www.nfacc.ca/pdfs/codes/equine_code_of_practice.pdf. Accessed May 24, 2019.

    • Search Google Scholar
    • Export Citation
  • 15.

    Gibson TJ, Bedford EM, Chancellor NM, et al. Pathophysiology of free-bullet slaughter of horses and ponies. Meat Sci 2015;108:120 124.

  • 16.

    Machado M, Maria R, Silva G, et al. Bone and brain lesions in horses following euthanasia with fire gun. Braz J Vet Pathol 2003;6:102 105.

  • 17.

    Millar GI, Mills DS. Observations on the trajectory of the bullet in fifteen horses euthanized by a free bullet. Vet Rec 2000;146:754 757.

  • 18.

    Thomson DU, Wileman BW, Rezac DJ, et al. Computed tomographic evaluation to determine efficacy of euthanasia of yearling feedlot cattle by use of various firearm-ammunition combinations. Am J Vet Res 2013;74:1385 1391.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 19.

    Humane killing of livestock using firearms. Human Slaughter Association. Available at: www.hsa.org.uk. Accessed May 23, 2019.

Advertisement