Gunshot Wound Management

Vol.18, No. 12 December 1996

V

HEINZ SYMPOSIUM 1996

Continuing Education Article

FOCAL POINT ★A basic understanding of ballistics helps the veterinarian select the most appropriate treatment for gunshot wounds.

KEY FACTS ■ The mass, velocity, design, and composition of projectiles influence their destructive properties. ■ Even low-velocity projectiles can inflict serious and sometimes fatal injuries. ■ High-velocity projectiles can cause massive tissue destruction because of their tremendous kinetic energy and the shock waves they send through adjacent tissue. ■ Failure to follow correct procedures for documenting and handling forensic evidence can adversely affect the outcome of litigation.

Gunshot Wound Management Tufts University

Michael M. Pavletic, DVM

P

rojectiles often cause injuries in humans and animals. A projectile is an object that is propelled by external force and that continues in motion by inertia. In veterinary medicine, gunshot wounds are the most common projectile injuries. The likelihood of a veterinarian seeing such injuries, however, depends on the location of the practice. In 1985, I conducted an epizootiologic study of gunshot wounds (111 in dogs and 10 in cats) seen as emergencies at Boston’s Angell Memorial Animal Hospital from 1972 to 1983. Most of the injuries took place in lower-income neighborhoods, which had a greater incidence of crime. Angell Memorial’s proximity to these areas and its established 24-hour emergency service explains the comparatively large number of cases seen during this period.1 More animals were shot in the evening and early morning hours than at any other time of day. In most cases, the animals had been left outdoors unsupervised. A larger percentage of the shootings occurred over the weekend (Friday night through early Monday morning). Handguns were the most common weapon documented (n = 95). Three animals that were shot with high-velocity rifle rounds were referred from rural areas. Six animals had shotgun wounds, and 17 had wounds from air-propelled BB or pellet guns. Incidental retained projectiles discovered on routine radiographs were not included in the study.1 Many of the injuries were misdiagnosed as vehicular trauma or bite wounds.1 Because the severity of gunshot wounds varies considerably, a basic understanding of ballistics will allow clinicians to select the most appropriate forms of treatment. This article reviews the ballistics, pathophysiology, and management of gunshot wounds.

BALLISTICS Ballistics is the science of the motion of projectiles in flight—from the point of initial propulsion to the final path through the target. Kinetic energy is a means of quantifying the destructive capacity of projectiles. The physics formula for kinetic energy outlines the relationship between projectile mass and velocity; this relationship explains, in part, the destructive capacity of projectiles: Kinetic energy = mass × velocity 2

2

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Doubling the mass doubles the kinetic energy of a projectile, but doubling the velocity quadruples the kinetic energy. Other factors, however, influence the severity of trauma caused by projectiles.2,3 Figure 1—Two .38-caliber rounds retrieved from the brain of an aggressive pit bull. The lead core has completely sep-

PROJECTILE VELOCITY arated from the partial jacket in one bullet. The second Low-velocity projectiles bullet, minus the exposed lead tip, is substantially intact are classified as those that after passing through the skull. travel less than 1000 feet/ sec; medium-velocity projectiles travel between 1000 and 2000 feet/sec; and highvelocity projectiles travel faster than 2000 to 2500 feet/sec. Most handguns are considered to be low-velocity weapons. Rifles can generate the higher velocities Figure 2A desired for military and hunting purposes.2,3 PROJECTILE CALIBER, DESIGN, AND COMPOSITION The term caliber refers to the diameter of the projectile or bore (interior diameter) of a gun barrel. Caliber is measured in fractions of an inch or in millimeters. Larger caliber suggests greater projectile mass. Because of differing shapes and compositions of projectiles, however, the mass and velocity of projectiles of a given caliber vary widely.2,3 A cartridge, or round, consists of the primer, case, powder, and bullet. When a weapon’s firing pin strikes the primer within the base of the casing, the powder charge ignites and propels the bullet forward. For most rifles and handguns, spiral grooves within the barrel (rifling) impart rotation, or spin, on the bullet’s longitudinal axis to

Figure 2B Figure 2—(A) Lateral and (B) dorsoventral radiographic

views of a paralyzed cat. A BB entered the spinal canal through an intervertebral foramen. Despite its modest velocity and mass, this air-powered projectile can inflict serious injury when fired from a weapon at close range.

stabilize its flight for greater accuracy. Shotguns and many air-powered weapons have smooth bores designed for the specific projectiles fired.2,3 Bullets can be designed to help maintain their shape, to deform in a controlled fashion, or to fragment on impact. Most bullets are composed of lead, with variable amounts of antimony added as a hardener. A lead core may be encased in a metal jacket composed of copper, cupronickel, brass, or soft steel to limit bullet deformation from the heat, friction, and tremendous pressures that can be generated as the bullet passes through the barrel. A jacket also influences bullet deformation when the bullet strikes and passes through a target. Heavier bullets have greater penetration than smaller high-velocity projectiles, which rapidly dissipate their kinetic energy.2,3 By international law, military projectiles must have a full-metal (full patch) jacket to limit the additional tissue destruction associated with bullet deformation and fragmentation. Civilians, however, can purchase nonjacketed or partially jacketed bullets to be used for hunting and self-defense. 2,3 In partially jacketed bullets, a portion of the lead core is exposed, which allows the nose to partially flatten, or mushroom, in a controlled fashion. Although penetration may not be as deep as that seen with fully jacketed bullets, expansion of the exposed lead tip enhances the projectile’s impact, destructive capacity, and killing potential (Figure 1).

KINETIC ENERGY ■ PROJECTILE CHARACTERISTICS ■ JACKETS

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Commercially available trauma to tissue and the rehollow-point bullets and exgional circulation. Fractured ploding bullets, which are bones, torn vessels, ruptured intended for security or selfbowels, and massive contudefense purposes, are desions can occur without disigned to rapidly deform rect contact with the projectile. and fragment to enhance Edema and vascular thromabsorption of the projectile’s bosis progress for hours after kinetic energy. Some indiinjury and can result in a viduals flatten the ends of greater volume of tissue bullets and score crossed necrosis than was originally grooves on the surface (soestimated at initial wound called dumdum bullets) for assessment. 2–4 Traumatized 2,3 tissue, vascular compromise, similar purposes. Figure 3A Exploding and “prefragforeign debris, and the inocmented” projectiles were ulation of bacteria into the more recently introduced depths of the wound increase for use against skyjackers the risk of infection.2–4 The specific gravity of the and other criminals. The tissues struck also influences projectiles impart a “knockthe nature and severity of down” effect on the person the wound. Rigid structures struck by maximizing ab(e.g., cortical bone) can sorption of kinetic energy. shatter on impact, whereas In addition, they reduce the softer cancellous bone (e.g., dangers associated with the distal femur) is less prone to round exiting the body and fragmentation. Low-velocity striking the plane’s fuselage bullets can punch through or passengers inside the soft cancellous bone. Fragpressurized airplane cabin. ments of cortical bone or Depending on the composi- Figure 3B tion and design of the ex- Figure 3—Two examples of .177-caliber air-rifle pellets. the projectile can become ploding bullet, undetonated The pointed pellet (A) is designed to deeply penetrate tis- secondary projectiles, enrounds retained in the body sue, whereas the waisted pellet (B) is designed to flatten hancing regional tissue injury.2–4 Elastic tissues, such can pose a hazard to the sur- and rapidly decelerate on impact. as lung and muscle, can geon removing the projecstretch to a variable degree, tile. Body temperature or thereby better maintaining their architectural integrity jostling of the bullet can cause unstable bullets to exand reducing the amount of tissue destruction. In conplode during removal. A projectile of unknown type trast, the liver, with a specific gravity similar to muscle, should be handled gently during removal and storage.2,3 is less cohesive and resilient. The liver fractures rather DESTRUCTIVE CAPACITY OF PROJECTILES easily on impact.2–4 Tissue in the immediate path of a bullet is lacerated PROJECTILE WEAPONS and crushed. The damage that the shock waves released Compared with most handguns, rifles can accurateby high-velocity projectiles cause to adjacent tissues can ly fire large, high-velocity projectiles. Although most be more difficult to conceptualize. Soft tissue and bone handguns are considered to be low-velocity weapons, balloon outward from the path of the passing projecrounds from a more powerful handgun can exceed tile, thus briefly creating a cavity. This phenomenon, 1000 feet/sec (medium-velocity range) and cause termed cavitation, can produce a temporary cavity that is up to 30 times the diameter of the bullet. considerable tissue destruction. Lower-velocity During cavitation, a vacuum forms. This vacuum can weapons, including air-powered weapons, can prodraw contaminants and surface debris from both the enduce serious and lethal wounds in humans and anitry and exit sites into the temporary cavity. The crushing mals, although they do not produce extensive tissue and compression effect of cavitation results in extensive trauma. EXPLODING PROJECTILES ■ TISSUE DAMAGE ■ CAVITATION

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Air-Powered Projectiles In contrast to conventional handgun and rifle cartridges, in which projectiles are propelled by gases released from exploding gunpowder, BB and pellet guns primarily rely on compressed air that is released from a chamber to propel the lightweight BB or pellet. Air rifles can achieve velocities comparable to many handguns, but the rounds rapidly lose velocity over comparatively shorter distances because of their shape and lighter weight.2–4 BBs (.175 caliber) and pellets (.177, .20, and .22 calibers) are currently used for target practice and hunting of small animals. Unlike the round BB, pellets come in various shapes, which modify their performance (Figures 2 and 3). Retained pellets and BBs are common incidental findings on radiographs. They rapidly decelerate over relatively short distances as a result of air resistance. They slow down further on impact with the elastic skin. Thus, BB and pellet penetration often is limited to the hypodermis and underlying musculature.2–4 When fired at close range, however, they can penetrate deep into the body. Shotguns Shotguns are smoothbore, long-barreled guns designed to fire a grouping of spheres. These pellets (“shot”) vary in size and number, depending on the bore of the shotgun and the game hunted. The pellets emerge from the muzzle in a

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Figure 4A

Figure 4B

Figure 4C Figure 4—(A) High-velocity rifle round that entered the up-

per right facial area of a dog that was referred from a rural area. (B) The mandible and maxilla were shattered into multiple fragments. Extensive soft tissue destruction secondary to cavitation and fragmentation of the bone and portions of the bullet are evident. (C) There was a large, explosive exit wound on the left side of the head. Radiographs demonstrated a small trail of lead fragments, with the bulk of the highvelocity round exiting the body despite passage through dense bone. These findings are characteristic of a high-velocity rifle round, probably a partially jacketed hunting round.

BB GUNS ■ PELLET GUNS ■ SHOTGUNS

tight cluster but disperse as they move down range in a widening, funnel-like pattern. The muzzles of shotguns can be modified in design (choke) to vary the pattern or dispersion of the shot over a given distance.2–4 Shotguns can also fire heavy lead projectiles called deer slugs. The hollow base of the slug expands to seal the bore of the shotgun on detonation of the charge. Because shotguns have smooth bores, angular grooves etched on the outer surface of the deer slug impart a spin on this projectile to stabilize its flight.2,3 A variation, called sabots, are solid projectiles cased in plastic sleeves that seal the barrel. The sleeves are shed during flight. When a shotgun is fired at close range (within 15 yards), the dense cluster of pellets, presented in a compressed surface area, results in massive tissue destruction. When the shotgun is fired at very close range, the cardboard or plastic wadding that is used to separate the pellets from the powder charge in the shell can also be driven into the wound. When shotguns are used beyond their effective hunting range (20 to 40 yards), the pattern of pellets is more widely dispersed, pellet velocity is greatly reduced, and the capacity for the pellet to inflict life-threatening injury diminishes.2,3

MANAGEMENT OF PROJECTILE WOUNDS Management of gunshot wounds varies according to the type of weapon, the kinetic energy of the projec-

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tile, and the location of the a Labrador retriever with elewound(s). The nature of the vated lead blood levels and wound can help determine clinical signs compatible the weapon used. If a bulwith plumbism (without evilet is retained in soft tissue dence or history of lead conwithout striking bone, it can sumption). This dog had be surmised that the round numerous retained birdshot was low velocity. However, if pellets in the thoracic area. the round struck and shatThe exposed surface area tered dense bone of a largeof a retained lead projectile breed dog and had sufficient and the location of the proenergy to exit the body, a jectile in the body can inhigh-velocity rifle round or fluence the degree of lead more powerful handgun Figure 5A absorption. Lead has greater should be suspected4 (Figure solubility when exposed to 4). synovial fluid. When such The size and shape of exposure occurs over long entry and exit wounds can periods, lead poisoning has be somewhat misleading. occurred in humans.5,6 Undeformed, fully jacketed Although exit wounds are bullets expose little of the generally larger than entry surface area of the lead core, wounds because of the outthus limiting the risk of ward or explosive egress, exit plumbism. Therefore, conwounds may be smaller than cern over lead poisoning entry wounds if velocity and seldom justifies removal of projectile mass are diminlead projectiles.5,6 ished at the point of exit In wounds from highfrom a body region. A tumvelocity projectiles, the sigbling projectile that presentnificant tissue destruction ed its long side at entry also Figure 5B can produce a comparatively Figure 5—(A) A .22-caliber gunshot wound to the head of (especially when bone has large entry wound and en- a cat. The projectile passed through the nasal cavity and been struck) usually rehance tissue destruction the maxillary bone, destroying adjacent teeth. It then quires wound exploration within its path. At very close passed through the oral cavity and fractured the left and debridement. When range, explosive gases re- mandible before exiting the left lateral facial skin. The tissue viability cannot be leased at the muzzle can bal- metallic probe demonstrates the pathway of the bullet. determined immediately, Soft tissue trauma was exacerbated by bone fragmentation. many of these wounds reloon the entry wound.3 (B) The wounds were opened, explored, and debrided. Low-velocity projectiles quire variable periods of Free fragments of bone and broken teeth were removed. that have not entered a joint The maxillary defect was closed by apposition of viable open wound management or struck an important body mucosa bordering the surgical site. The mandibular and staged debridement.2–4 structure can create wounds wound was handled similarly, and drainage was estab- The more powerful lowthat can be treated by local lished. Broad-spectrum systemic antibiotics were adminis- velocity projectiles can also shatter bone, thus necessicleansing and lavage of the tered. The patient recovered completely. tating wound exploration, entry and exit sites. Wound debridement, fracture stabidebridement may be limited lization, and drainage. to the skin and underlying Gunshot wounds to the abdominal cavity should be fascial tissues. A topical dressing is applied to the wounds. explored as early as feasible because of the significant Systemic antibiotics may be advisable in selected cases risk of peritonitis secondary to bowel perforation4 (Fig(Figure 5). Easily accessible bullets can be removed, but ure 6). From an historical perspective, 90% of Civil attempts to explore for deeply retained projectiles simply War patients with abdominal gunshot wounds died of to retrieve the round should be discouraged.4 Lead poisoning (plumbism, saturnism) secondary to retained properitonitis.7 During the Vietnam War, rapid evacuation of patients from the combat field to the surgical suite jectiles is rare in humans and animals. Only once did I see ENTRY WOUNDS ■ EXIT WOUNDS ■ WOUND THERAPY

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reduced the mortality rate to the area until ligation or re9%.7 I have seen severe peripair can be performed. In tonitis in several animals in the interim, judicious intrawhich abdominal explovenous fluid support should ration was not performed. be provided. Most of these patients apGunshot wounds to the peared stable on presentation brain are associated with a but developed massive perihigh mortality rate in hutonitis from bowel perforamans and animals. After a tion a few days after injury. careful physical and neuroUnlike penetrating ablogic examination, specific dominal wounds, many thodiagnostic tests (including racic gunshot wounds may computed tomography and not require exploration. Ex- Figure 6A magnetic resonance imagploration is required, howing) can be selected. In huever, if hemorrhage is life mans, carotid arteriography threatening, air leaks are unis commonly performed responsive to thoracostomy to assess the integrity of the tube insertion and continublood supply to the brain.10,11 Fortunately, dogs have exous suction drainage, or the cellent collateral circulation esophagus or other adjacent to the brain, even when vital structures are impacted both carotid arteries are lig(Figures 7 and 8). Projectiles ated. can pass through the chest Gunshot wounds to the and into the abdominal cavhuman brain usually are exity, thus necessitating abplored to remove possible dominal exploration.2–4 Pellets or BBs that enter sources of infection (debris, the eye can elicit a severe contaminants, and bone foreign-body reaction. In Figure 6B fragments). Although this these cases, the projectile Figure 6—(A) Air-powered BB gun injury to the abdomen approach may be justified at must be removed. Closure of of a Siamese cat. At presentation, the cat was depressed times in small animals, data the scleral or corneal perfo- and had abdominal pain. (B) Laparotomy revealed multi- regarding the management ration may be complicated ple perforations of the bowel wall. The probe illustrates of gunshot wounds to the by the ragged entry wound one of the perforating wounds to the small intestine. Note brain in animals are lacking. created by the pellet or BB. the small BB retrieved from the bowel site. (From Pavletic Retained projectiles may be MM: Atlas of Small Animal Reconstructive Surgery. Occasionally, projectiles pass difficult or impossible to Philadelphia, JB Lippincott Co, 1992. Reproduced with through the eye and into the permission.) approach without causing orbit. Extensive hemorrhage more serious injury to the may occur in the retrobulbar brain. There are reports of space, or the optic nerve may be struck. More powerful humans surviving and functioning satisfactorily with reprojectiles may enter the brain through the thin orbital tained projectiles in the brain. The same is true for small bone.8,9 Radiographs and computed tomography help animals that have sustained low-velocity gunshot define the location of the projectile. Complete destrucwounds.12,13 Careful evaluation of the injury and patient are required to determine the best approach to the tion of the ocular architecture necessitates removal of emergency medical and surgical management of inthe eye. tracranial projectile trauma. Gunshot wounds involving the maxillofacial area The neck is especially prone to serious injuries bemay threaten the patient’s ability to breathe if extensive cause of the concentration of vital structures in this hemorrhage and swelling obstruct the upper airway. small anatomic region. The larynx, trachea, spinal cord, Suction of blood and saliva may provide temporary recranial nerves, carotid and jugular vessels, pharynx, and lief, but an emergency tracheostomy may be the best esophagus are among the vital structures susceptible to way to ensure a patent airway. Bleeding may be conprojectile trauma. Major problems in the management trolled temporarily with moderate external pressure to PERITONITIS ■ THORACIC WOUNDS ■ EYE WOUNDS

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Figure 7A

Figure 8A

Figure 7B Figure 7—(A) Pneumothorax secondary to shotgun pellets. (B) A thoracostomy tube was inserted and connected to a chest drainage system. The patient recovered completely.

of cervical gunshot wounds are the difficulty in diagnosing some deeper wounds and the possible resultant delay in repair, which could result in serious complications. Cervical gunshot wounds in humans are often explored because of the risk of esophageal perforation and major vascular injury. In dogs, major esophageal perforation (which could result in cervical and anterior mediastinal infection) may be ruled out by esophagoscopy and radiographic contrast examination.4,11–19 Cervical exploration is also warranted in the presence of profuse or persistent bleeding, expanding hematomas, wounds to the larynx or trachea, serious spinal cord injuries, or unstable vertebral fractures11,14–19 (Figure 9). Gunshot wounds to bones are treated by internal or external stabilizing devices. Because management of extensive orthopedic injuries can be difficult and costly, limb

Figure 8B Figure 8—(A) Cardiac tamponade secondary to shotgun

pellets penetrating the pericardium. (B) Pericardiocentesis was followed by pericardiectomy. The patient recovered completely.

amputation may be advisable in some cases (Figure 10). Bullets can migrate through fascial planes or gravitate in the thoracic and abdominal cavities. Projectiles can enter the vascular system and embolize to distant anatomic locations. Projectiles in humans also have been documented to enter a bronchus and then be coughed up or swallowed.2,3 A pellet that entered the

CERVICAL WOUNDS ■ BONE WOUNDS ■ BULLET MIGRATION

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Figure 9A

Figure 10A

Figure 9B

Figure 10B

Figure 9—A dog that had been shot in the neck with a

Figure 10—(A) A gunshot wound to the right humerus and

handgun was presented with extensive subcutaneous emphysema and pneumomediastinum. (A) Manual compression of the skin highlights the extensive air accumulation. (B) A hole in the trachea at the level of the thoracic inlet was identified and sutured closed. The subcutaneous emphysema rapidly decreased within 72 hours after surgical correction. The patient recovered completely.

scapulohumeral joint of a cat. (B) Because of the extensive soft tissue and orthopedic trauma, the limb was amputated. The exact weapon was unknown, although a .22caliber round was suspected.

urinary bladder of a Labrador and later caused acute urethral obstruction has been documented4 (Figure 11). When the pathway of projectile(s) cannot be clearly documented, multiple radiographs of the body should be taken to determine the pathway and to rule out bullet migration. Retained projectiles from a previous shooting can create confusion in the diagnostic evaluation of trauma patients. Clinicians may mistakenly conclude that an injury is a gunshot wound if a bullet is visible on the radiograph. The patient must be inspected carefully for entry wounds and whether the presenting wounds or clinical signs are compatible with a gunshot wound2–4 (Figure 12).

LEGAL CONSIDERATIONS Forensic evidence of a shooting may be requested by owners, game wardens, and attorneys.20–23 Veterinarians must be able to document such evidence or request assistance from an experienced pathologist. Basic protocols and responsibilities involved with handling forensic evidence must be followed, or legal cases will be contested easily. Detailed records should include notes of all conversations. A complete set of quality radiographs and color photographs of the entire animal should be taken to illustrate the general position of the injuries. This will help orient those reviewing the case. Close photographs of individual injuries should include an area 15 cm around the wounds. A metric ruler should be included

RETAINED PROJECTILES ■ FORENSIC EVIDENCE ■ DATA COLLECTION

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in the photographs to indito a piece of rigid material, cate scale. The photographs and then frozen for analysis are labeled with the date, to determine the presence of case number, and examinpropellant and projectile er’s initials. Projectiles residue. This tissue specimen should be photographed in should not be washed or situ before their removal.20 placed in formalin.20 Flexible plastic probes or Careful examination and catheters can be used to collection of tissues surroundhighlight the course of a ing the path of a projectile projectile. Metallic probes are useful in determining should not be used because whether game has been illethey can separate tissues gally killed by a gun during during insertion and possi- Figure 11—Lateral radiograph of a Labrador retriever with restricted bow-hunting seably scratch the surface of a acute urinary tract obstruction secondary to migration of a sons. Some hunters insert a retained projectile, thereby .20-caliber Sheridan pellet, which lodged at the os penis. broad-head arrow into a gundisturbing rifling marks on The dog had been shot in the urinary bladder; a small scar shot wound to mask the nawas noted in the skin where the projectile originally en- ture of the weapon. Flesh its outer surface.20 When feasible, an experi- tered the abdominal cavity. A urethrotomy successfully re- along the path of the bullet enced, board-certified vet- moved this air-powered pellet. can be collected to recover erinary pathologist should particles of lead released by perform the detailed postfrangible projectiles. Lead mortem examination. Other preexisting medical or residue can be identified by atomic absorption specphysical conditions may have affected the circumtrophotometry in tissue surrounding the tract. Tissue samstances of the animal’s demise. Tissue samples are taken to confirm the presence of any suspected diseases, determine the age of a wound, and help distinguish entry from exit wounds. Tissue samples occasionally are taken for more detailed testing and analysis by lawenforcement officials. Information commonly requested in court relates to the number and location of wounds, features of the wounds and related tissue areas, course of the projectiles, angle of fire, projectiles and foreign debris recovered, cause and time of death, and details pertaining to the handling and disposition of specimens collected.20 Entry wounds are closely inspectFigure 12A Figure 12B ed to determine the proximity of the weapon to the Figure 12—(A and B) Two radiographic views of a fractured femur in a cat. This comminuted animal. A 15-cm square fracture was not caused by a gunshot wound, as the admitting clinician originally suspected. The retained BB was an incidental finding. No entry wound was present, and this air-powaround entrance wounds ered projectile was not capable of this degree of orthopedic trauma. should be removed, pinned REQUIRED PHOTOGRAPHS ■ TISSUE SAMPLES ■ WOUND DESCRIPTION

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ples taken from a separate, uninvolved body region of the carcass serve as a control.20 Examination of gastric contents can also help the pathologist determine the circumstances of the incident.20–23 The lands (elevated borders) and grooves of a rifled barrel embed marks on jacketed and nonjacketed bullets. Occasionally, the lead core separates from the outer jacket. Retrieval of the jacket is of greater importance because the rifling marks are scored on its outer surface. Bullets should be handled carefully because scratching the surface can damage the rifling marks used to help identify the weapon. Forceps can be padded with tape to avoid this problem. The bullet should be washed with water and alcohol and then allowed to air dry. The washing removes blood and tissue fragments.20 The bullet can be marked on its base (bottom) to ensure that it can be identified later. Close-up photographs of the bullet ensure its identification. All projectiles should be wrapped in facial tissues and placed in vials or containers that can be sealed with tape. The body region from which each projectile was retrieved must be clearly identified, and each projectile must be placed in a separate, marked container. The container is identified with the date, time, case number, and owner’s name and it is initialed by those

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present at the necropsy. An indelible marker should be used on the container or on a nonremovable label.20 The projectiles should be secured from tampering or access by other individuals. Projectiles are turned over only to a qualified law-enforcement officer. Any persons receiving the specimens must add the time and date of the transfer and their initials to the container.20 Owners often ask for the projectiles. Such requests should be denied because the projectile could be altered or lost, thus reducing the credibility of the evidence gathered. Errors in collecting data and recording pertinent information can adversely affect the outcome of a case, despite the best intentions of the veterinarian. Therefore, careful attention to the legal issues discussed in this section will help clinicians avoid the embarrassing errors and pitfalls associated with inappropriate case preparation in a court of law.

About the Author Dr. Pavletic, who is a Diplomate of the American College of Veterinary Surgeons, is Professor and Head of the Department of Small Animal Surgery, School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts.

REFERENCES

Interested in writing for COMPENDIUM? For small animal articles, please contact Dr. Douglass Macintire (email macindk@ vetmed.auburn.edu; phone 334-844-6032). For exotics articles, please contact Dr. Branson Ritchie (phone 706-542-6316; email [email protected]).

1. Pavletic MM: A review of 121 gunshot wounds in the dog and cat. Vet Surg 14:61–62, 1985. 2. Pavletic MM: Gunshot wounds in veterinary medicine: Projectile ballistics—Part I. Compend Contin Educ Pract Vet 8(1):47–60, 1986. 3. Pavletic MM: Gunshot wounds in veterinary medicine: Projectile ballistics—Part II. Compend Contin Educ Pract Vet 8(2):125–134, 1986. 4. Pavletic MM: Atlas of Small Animal Reconstructive Surgery. Philadelphia, JB Lippincott Co, 1992, pp 92-108. 5. Dillman RO, Crumb CK, Lidsky MJ: Lead poisoning from a gunshot wound. Am J Med 66:509–514, 1979. 6. Leonard MH: The solution of lead by synovial fluid. Clin Orthop 64:255–261, 1969. 7. Greisman HC: Wound management and medical organization in the Civil War. Surg Clin North Am 64:625–638, 1984. 8. Sevel D, Atkins AD: Pellet gun injuries of the eye. S Afr Med J 54:566–568, 1978. 9. Slatter D: Fundamentals of Veterinary Ophthalmology, ed 2. Philadelphia, WB Saunders Co, 1990, p 490. 10. Podgorny G, Stanley L: Gunshot victims. Reg Nurs 45: 47–51, 110, 112, 1982. 11. Swan KG, Swan RC: Gunshot Wounds. Littleton, MA, PSG Publishing Co, 1980. 12. Zimmer MA, Hoppe WE: Gunshot wound in a head of a dog. VM SAC 74:814–815, 1979. 13. Pavletic MM: Unpublished data, School of Veterinary Medicine, Tufts University, North Grafton, MA, 1992. 14. Small IA: Reconstructive prosthetic surgery of massive craniofacial injury. J Oral Maxillofac Surg 41:609–612, 1983.

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15. Popovsky J: Perforations of the esophagus from gunshot wounds. J Trauma 24:337–339, 1984. 16. Ordog GJ, Albin D, Wasserberger J, et al: 110 Bullet wounds to the neck. J Trauma 25:238–246, 1985. 17. Massac E, Siram SM, Leffall LD: Penetrating neck wounds. Am J Surg 145:263–265, 1983. 18. Yap RG, Yap A, Obeid FN, Horan DP: Traumatic esophageal injuries: 12 Year experience at Henry Ford Hospital. J Trauma 24:623– 625, 1984. 19. Sulek M, Miller RH, Mattok KL: The management of gunshot and stab injuries of the trachea. Arch Otolaryngol Head

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Neck Surg 109:56–59, 1983. 20. Green PD: Protocol in mediolegal veterinary medicine. II. Cases involving death due to gunshot and arrow wounds. Can Vet J 21:343–346, 1980. 21. Dillon JH: Firearms and toolmark identification. National College of District Attorneys, 1986. 22. Dillon JH: Ballistics and firearms. National College of District Attorneys, 1986. 23. Peterson GF: Gunshot and shotgun wounds. National College of District Attorneys, 1986.