Melinda D. Merck1, DVM
Introduction and Considerations
There are numerous situations that may qualify as animal cruelty depending on the governing laws: starvation, dehydration, untreated medical problems, failure to provide relief from extreme environmental conditions, hoarding, embedded collars, physical or sexual abuse, poisoning, animal fighting, and so on. Physical abuse cases often have neglect as a component of the crime. Animal cruelty is basically any action or lack of action that results in unjustifiable or unnecessary suffering, illness, injury, or death of an animal. It is important that veterinarians have an understanding of the animal cruelty laws so they can respond appropriately and assist the investigators and prosecutors in the potential case.
There are several considerations to first determine if the injury is a result of accidental versus non-accidental causes. The veterinarian must draw on their own experience with known accidental injuries and compare those findings to the evaluation. The information provided by the caregiver and/or the investigator is critical to properly evaluate a possible case of cruelty, whether the animal is alive or deceased. A necropsy should never be performed without investigation findings and crime scene information including photographs of the scene. The environment and husbandry for the animal directly affect the health of the animal and must be analyzed along with physical exam findings. Animal cruelty should be suspected in every case where the history, crime scene findings, and environmental conditions do not support the exam findings. Aberrant findings should not be disregarded for they are often the key piece of evidence that the injuries sustained are non-accidental. The goal of reporting suspected abuse is for an investigation to be conducted. It takes all parties to fulfill their role in the investigation to prove and disprove possible elements of the crime.
When examining an animal, there must be full documentation of all the findings. The exam should include written and photographic and/or video documentation. Make sure the evidence is photographed in situ prior to collection. All notes, recordings, photographs, and reports are considered evidence and will be reviewed by the investigator, prosecutor, defense attorney, and judge. Every effort should be made to collect evidence prior to treatment to prevent contamination of the evidence. After treating the animal, it is vital to document the process of the animal's recovery including weight gain and by repeating appropriate tests. As the animal recovers, the medical records and/or reports should include the timelines for treatments and assess the reasons for the animal's recovery.
Forensic Necropsy Procedure Considerations
The necropsy procedure involves a process of documentation and examination of the external and internal body. Photography starts with the body still in the package or bag. Photos with and without a photo scale should be taken of any evidence where the size is important. The external body should be examined for trace evidence, foreign material, bodily fluids, and obvious area of trauma. External wounds or evidence of injury such as contusions should be shaved and measured. The necropsy may be performed in lateral or dorsal recumbency. The skin should be reflected to identify underlying injuries. The dissection and opening of body cavities should be done based on the apparent injuries, avoiding major blood vessels which can contaminate the field and distortion or alteration of wounds. Flap dissection should be used to analyze and follow wound tracks through tissue such as gunshot wounds or sharp force penetrating injuries. It is important to consider skin tension lines and avoid manipulation of skin or wound tracks which can distort the weapon characteristics. It is best to examine the skin and soft-tissue wound characteristics first without manipulation and then with gentle manipulation to restore skin tension. Scotch tape may be used to re-appose the wound edges to discern blade characteristics such as serration. The use of a necropsy exam form and diagrams are recommended to ensure complete examination and documentation. The form also corresponds to the forensic report form making report writing easier. The deceased animal intake form is used to document case information when receiving the body. The evidence-chain of custody log and photo log are also forms that should be used.
Examples of Types of Abuse
The legal definition of neglect varies by jurisdictions. It has traditionally been defined as a passive act or the lack of action that results in the neglect of an animal. It is critical for the veterinarian to understand the nuances of the laws including local, state, and federal, in order to properly assist the investigator and prosecutor on the case. Neglect can be anything that causes the animal to suffer. It can also be defined as anything that is inadequate or inappropriate for the animal, taking into account environmental conditions, the species, gender, size, and age of the animal. Neglect can take many forms that negatively impact the animal's physical and mental well-being. These include the lack of or inappropriate shelter, food, water, bowls for food and water, tethering, preventative health care, medical treatment, embedded collars, and heavy chains.
Another consideration in neglect is the mental well-being of the animal in the form of boredom, distress, and emotional maltreatment. Consideration must be given to the species, gender, breed, and age of the animal to determine what the mental needs of that particular animal are. Confinement and lack of stimulation lead to another form of suffering, boredom, which has physical and psychological impacts on the animal. The degree of boredom for an animal is most evident when one observes the behavior after the environment is changed to enriched conditions. Distress manifests as a result of how an animal copes with an unpleasant affect (physical or emotional) such as boredom, pain, thirst, hunger, loneliness, or fear. Evidence of unpleasant emotions in animals is fear, phobias, anxiety, separation anxiety, loneliness, boredom, frustration, anger, grief, helplessness, hopelessness, and depression. Emotional maltreatment refers to the link between emotional states and physical health. Emotions can cause distress, anguish, and suffering. They can be associated with long-term problems such as separation anxiety, decreased learning, depression, difficulty with social interactions, or even physical manifestations of illness.
Starvation is the process of the body consuming itself, both fat and protein, which causes vital members of the body to cease to function. It causes immune suppression making the animal more susceptible to infections. You need to get the initial body weight and record the body condition score. It is also important to show the subsequent weight gain in response to treatment, especially if the only treatment was giving the animal food and water. If the animal is wearing a collar and it is loose, then you need to measure the circumference of the neck and the collar for comparison. This is especially important if the animal was tethered outside because at some point that collar had to fit or the animal would have got loose. If the collar is loose enough that the dog could slip out, then you have to question what prevented the animal from escaping. Usually, it is because the animal was too sick or weak to escape and seek food and water.
It is important to run bloodwork on these cases as soon as possible after they are impounded and preferably prior to initiating treatment. Blood may be drawn at a shelter by the staff and then held pending the veterinarian's instructions. Findings on labwork in starvation cases depend on secondary infection and the state of starvation. They may include prerenal azotemia, anemia, elevated liver enzymes, increased total protein, increased globulin, low albumin, very high CPK, monocytosis, leukocytosis, stress-leukogram, ketonuria, and electrolyte abnormalities. Low glucose may or may not be seen - the body is doing everything it can to maintain the blood sugar. In the terminal phase of starvation the glucose may be low. For cases of animals that have not eaten for 4–5 days or prolonged periods of time, inanition, it is possible to see slightly low AST, slightly low calcium and/or a slightly elevated total bilirubin.
There are many different types of non-accidental injuries. They include penetrating injuries, non-penetrating injuries, burns, gunshot wounds, asphyxia, drowning, poisoning, ritualistic crime, sexual assault, and animal fighting injuries. There are several considerations to first determine if the injury is a result of accidental versus non-accidental causes. The veterinarian must draw on their own experience with known accidental injuries and compare those findings to the evaluation. Another source of information is emergency veterinarians who have a wealth of knowledge and experience with trauma though some of their cases may have been undetected abuse. The information provided by the caregiver and/or the investigator is critical to properly evaluate a possible case of cruelty. The environment and husbandry for the animal directly affect the health of the animal and must be analyzed along with physical exam findings. Animal cruelty should be suspected in every case where the history, crime scene findings, and environmental conditions do not support the exam findings.
Burns may be caused by a variety of methods including chemicals, thermal, scalding, and fire. The appearance of the burn provides several clues as to the cause of the burn. Burns are usually a patterned injury that reflects the cause of the injury. The proper interpretation of the burn patterns can reveal the exact nature of events which may support or refute the history. A determination of where the burn started on the body may be made when there are more severe burns confluent with more superficial burns. Splash or spill burns have trickle-like areas that are usually more superficial than where the liquid first contacted the body. A burn pattern that is evenly distributed with the same degree of injury is indicative of an even rate of burn.
Blunt Force Trauma
With every animal cruelty case, one must consider the animal suffered blunt force trauma in addition to any other injuries. Contusions are very hard to see on the skin surface of animals unless there is light-colored skin and the fur is parted all over the body to inspect for discoloration. It can take hours for bruising to show up on a live animal, so re-inspection of the body should be done every few hours. In deceased animals, the skin should be reflected all over the body to reveal subcutaneous hemorrhage. Sometimes the hemorrhage is in the deeper muscle next to the bone, such as the rib cage, and does not extend to the subcutaneous layers, especially if the survival period was very short after the injury. Careful dissection of the muscle layers can reveal the deeper evidence of trauma. The size and shape of the contusions can help determine what was used to cause the injury. There may be a denser area of hemorrhage with seepage into the surrounding tissues. It is the denser area that provides the clues to the cause. Petechiae may be seen on the pinnae and horizontal ear canal with blunt force trauma to the head. The petechia in the ear canal is a unique finding in dogs and cats due to the shape of their ear canal. Frank hemorrhage may be seen inside the ear due to a ruptured tympanic membrane. The common rule-out for any hemorrhage is clotting disorders which have a wide variety of causes, so a full workup should be conducted.
The causes of non-accidental injury are limited only by the perpetrator's imagination. To try and surmise the cause and/or weapons used, one must first examine the body for injury patterns. These will give the greatest clues as to the cause of injury. When weapons are used, either in penetrating or non-penetrating injuries, a corresponding weapon pattern may be found on the body. These can be in the form of distinct bruising, skin injury, or damage to bones. If a significant time period has elapsed since the injury occurred, the bruising may spread obscuring any distinct weapon patterns. The skin injury may present as patterned hair loss due to crushing forces, abrasions, or full-thickness defects. Bone fractures are caused by certain physical forces. Each fracture must be evaluated considering the type of force required to produce that particular type of fracture. In addition, the type of bone, the age of the animal, growth plate closures, the size of the animal, the density of the bone, and the location of the fracture are all factors in determining accidental versus non-accidental causes.
In these cases, you need to inspect the perineal area for evidence of trauma, abnormal swellings, contusions, or abrasions. Look for painful defecation, rectal or vaginal bleeding or abrasions. Use a UV light source to examine the fur and perineal area for bodily fluids and take samples. If the fluid is dried, moisten a cotton-tip applicator with distilled water and swab the area. Always take an additional control sample adjacent to the area of interest. Perform a vaginal exam to check the mucosa and cervical area for bruising or trauma. Take sterile swabs of the vaginal area for semen and STDs. You can make a separate slide and examine the swab sample for sperm. In addition, swab the gums, teeth and mouth area for possible DNA.
There are seven main objectives when analyzing gunshot wounds: determining entrance and exit wounds, retrieving gunshot residue, retrieving the projectile, retrieving any bullet cartridge or casing, determining trajectory, determining gunshot range, recording injuries.
There are some basic rules for determining entrance and exit wounds. In animals there is the advantage of fur being forced in or out, respectively. In general, entrance wounds are smoother and smaller than exit. Entrance wounds may have singed fur or skin indicating direction of travel. Abrasion rings may be found at entrance wounds where the bullet rubs raw the edges of the hole. The ring may be concentric or eccentric if the bullet entered at an angle causing a "bunching up" of skin. Entrance wounds may also have micro-tears at the edges if caused by a high-velocity gun. If the bullet entrance is at an area of thick skin or it is a distant gunshot to the head, the wound will usually have a stellar appearance. Contact gunshots produce splintered or star-shaped wounds because the bullet has a degree of wobble when first exiting the barrel of the gun. Exit wounds are usually larger and more irregular. They can be stellar, slit-like circular, crescent or completely irregular. "Shored" exit wounds have abraded margins because the skin was next to something firm when the bullet exited causing abrasions. Exit wounds through tight skin such as the head tend to be larger. Those through loose skin can be small and slit-like.
When retrieving projectiles, care should be taken not to cause damage that will interfere with the rifling marks on the surface of the bullet. These marks can be matched to the gun it was fired from. Use your fingers or cotton-wrapped forceps to grab the bullet. In shotgun injuries get a representative sample of the projectiles and any wadding if present. Place items in a paper envelope and then a small box for protection.
Ejected cartridges and casing may contain fingerprints. Exercise caution not to compromise their integrity during collection. All animals with gunshot injuries should have full-body radiographs. An exit wound does not necessarily mean the bullet exited. The bullet could have propelled bone fragments and tissue out, then rebounded back. Bullet emboli are possible.
Photograph each bullet wound before and after cleaning and shaving the wounds taking long-range and close-up views. Assign a number to each entrance wound and describe the location with a measurement to a landmark such as nipple, midline, and the animal's muzzle. Describe the appearance of the wound, path of the missile, injuries produced and exit or lodgment site. Save any powder grains and describe such as flake, ball or cylindrical. Shave and note powder tattoo patterns, abrasion rings, and muzzle imprints. When taking measurements, you can use a clock reference identifying the dorsal spine or head as 12 o'clock. Record the injuries created by the missile path.
Considerations for Accidental Causes
For all trauma cases, the most common rule-outs are motor vehicle accidents (MVA) and dog attack. With MVA injuries, there should be certain findings that are supportive of this type of cause. There should be dirt and debris on the fur; skin abrasions from the animal sliding on pavement or dirt; the abrasions should be lateral on the down side and medial on the opposite side; and frayed nails (most commonly found with cats). These findings are in addition to any injuries sustained from being hit, rolled under, or run over by a car such as blunt force trauma and fractures. In dog attacks, there should also be supportive findings of the cause. There is often dirt and debris in the mouth where the animal was dragged and shaken on the ground; head and oral trauma from being shaken by the neck or grabbed by the head; saliva on the fur which causes spiking of the fur; fur caught in the nails where the victim fought the attacker (especially cats); punctures of the skin which may be triangular or elliptical; and abdominal organ lacerations from compression and shaking with or without associated skin punctures.
1. Merck M, ed. Veterinary Forensics: Animal Cruelty Investigations. 2nd ed. Ames, IA: John Wiley Publishing; 2013.