Animal predation is part of the natural food chain, which returns the proteins, fats and carbohydrates of dead bodies
FIGURE2.24 Extensive mould formation and lack of putrefactive changes in a child who accidentally locked himself in a box and asphyxiated. The body was not found for 6 weeks.
FIGURE2.23 The mummified body of an absconder from a mental hospital who was found a year later in a hay barn. The dry environment had inhibited wet decomposition.
to other animals, some of it passing back to the vegetable kingdom through soil nutrition. All types and sizes of animal are involved, the largest seen by the author (BK) being a
‘near-miss’ by a Malayan tiger, who dragged a sleeping soldier from his tent. Most animal damage is more mundane, the beasts varying from ants to foxes, and from bluebottles to monitor lizards. Foxes can drag parts of a body away to a dis- tance of at least 2 miles.
The type of predation varies greatly with geography, season, and whether the dead body is indoors or out in the open. If it is lying in the countryside, large predators will cause prompt and severe damage, even complete destruc- tion being possible in a short time. In temperate countries, foxes and dogs form the main agents, and the body may be dismembered and scattered over a wide area, especially if advancing putrefaction makes disarticulation easy. If corpses are in inland waters, damage from water rats and fish is possible, as well as attacks from dogs and foxes, if the body lies exposed on the bank of a river or a lake.
The type of damage from canine and rodent predators is usually obvious, as the local removal of large amounts of flesh is usually accompanied by evidence of teeth marks. Rats and cats leave a crenated edge to fairly clean-cut wounds, the post- mortem nature of which is obvious from the lack of bleeding or an inflamed marginal zone. Mice rarely attack bodies, but may help to remove the dried, crumbling tissue of a mummi- fied corpse. The most active tissue removers are maggots, the larval stage of bluebottles (Calliphora) and flies (Musca). The use of the life cycle in timing death is dealt with elsewhere, but here we are concerned with their destructive effects on
corpses. In temperate zones their activity is seasonal, but in hot countries their predatory work is ever present. The adult insects lay eggs on the fresh corpse (or even on a debilitated live victim), choosing wounds or moist areas such as the eyelids, lips, nostrils and genitalia. Once skin decomposition begins, the eggs can be deposited anywhere. The eggs hatch in a day or so, and several cycles of maggot develop, shedding their cases at intervals, depending on the species.
FIGURE2.25 Loss of all soft tissues of head and neck, in areas not covered by clothing, by post-mortem animal predation.
FIGURE2.26 Post-mortem rat bites of the orbit. Such injuries are – not unnaturally – often regarded with suspicion by the police. The complete absence of bleeding or reddening of the wound margins, as well as the unlikely shape and situation of the injury, make its post- mortem origin obvious.
The maggots are voracious and energetic, first exploring the natural passages, such as mouth and nostrils, then burrowing into the tissues. They secrete digestive fluids with proteolytic enzymes that help soften the tissues, burrowing beneath the skin, and making tunnels and sinuses that hasten putrefaction by admitting air and access to external micro-organisms.
Successive waves of eggs are laid, producing new generations of maggots. Eventually, loss of tissue and drying make the host cadaver unattractive to egg-laying insects, and the later stages of decomposition become free from maggots.
Beetles and many other types of insect and arthropod join in the destruction, but one particular insect must be mentioned. This is the ant, which can attack the body soon after death before putrefaction begins. A common place for ant attack is around the eyelids, lips and on the knuckles.
The lesions are superficial ulcers with scalloped, serpiginous margins. They can be mistaken for ante-mortem abrasions, but their position, margins and lack of bleeding or inflam- matory changes usually make them easily recognizable.
Shapiro, however, has documented cases where extensive linear ant lesions have resembled ligature abrasions around the neck (Shapiro et al.1988).
Tropical ants can devour tissues to a considerable extent and, although stories of soldier ants reducing horses to skeletons within minutes are apocryphal, predation by large numbers of insects can be extensive.
In water, all manner of aquatic animals can mutilate immersed bodies, as well as land mammals if the corpse is in shallow water or grounded on a mudbank or the beach.
Large fish can be totally destructive, especially in tropical
Post-mortem damage by predators
FIGURE2.27 A body recovered from the Baltic Sea with numerous superficial skin defects on the face and neck due to post- mortem predation, probably by the crustacean Saduria entomon, shown in the inserted picture with a smaller shrimp in the middle.
FIGURE2.28 A post-mortem animal bite that was mistaken for a criminal assault. The old lady was found locked in with a cat, having died from a gastric haemorrhage. The wound has not bled, the margins are not reddened and tooth crenations can be seen round its edge.
waters, but even in temperate seas severe damage can occur.
Some of the victims of the Air India aircraft disaster near Ireland in 1985 were ravaged by sharks. Large gouges from the wound edges, punctures from teeth and extensive tissue loss, even with fractures of large bones such as the femur, characterize shark attacks.
Smaller fish can wreak severe damage, the prime example being piranhas, though many species will devour both fresh and decomposing bodies. Crustaceans are also predatory and can remove circular areas of skin to expose the subcuta- neous fat, which may detach inside the clothing to form masses of adipocere. Birds also cause damage, usually to the dead, though crows may mutilate live lambs. The habits of carrion birds, such as the vulture, are well known, but smaller birds will inflict injury on exposed bodies, espe- cially when putrefaction softens the tissues.
All animal predation varies in appearance according to the size and shape of the teeth or jaws of the predator, but all such post-mortem injuries have features in common. There is no bleeding apart from the minute quantity actually in the vessels of the damaged part, and certainly no active haemorrhage into the wound margins. Naturally, there is no oedema or reddening of the edges as might be seen in an ante-mortem wound earlier than the perimortal period.
Crenation of the edges is a useful guide where small rodents or other animals are involved, though large carnivores can make totally irregular tears in the tissue. Some animals, such as dogs and foxes, may leave punctured wounds adjacent to the damaged edge where sharp teeth have penetrated. On bones, the incisor teeth of rodents and larger carnivores can leave parallel gouges, which must not be mistaken for illicit human activities. In domestic surroundings, pets may inflict drastic post-mortem injuries if they are locked in with a dead person. Dogs and cats can cause injuries that puzzle those, such as the police, who are unaware of the possibility. Complete decapitation by Alsatian dogs has been seen by both of the authors, as well as genital injury.