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Home , Vipera berus

Bristol Medico-Chirurgical Journal July 1985

The Doctor and the

Philip Radford, M.B., Ch.B., D.C.H. Retired General Practitioner, Bristol

The goddess of health, Hygieia, was much ven- physical recovery. So it was reasoned that the eating erated, understandably, in the ancient Greek world; of a snake should impart some of its characteristics to her numerous statues usually represented her hold- man. Similarly, certain African tribesmen who yearn ing a serpent. Hygieia's father was Aesculapius, the for extra strength and speed eat the meat of the lion god of medicine, who developed his clinical skills as Fe/is leo or the leopard Felis pardus. physician to the Argonauts and made use of herbs in is a potent protein mixture and, as is treatment; the serpent and the cock were considered well known, the venoms of some species do have sacred to him. So the Greeks, when wanting a medical applications. Vipers produce venom which medical cure, sacrificed on altars erected in the is both haemolytic and cytotoxic: after a bite, pain, shrines of Aesculapius. In those times, the snake was local swelling and eccymosis result. The poison is thought of as being wise and statues of Aesculapius injected subcutaneously through the canals of the showed him holding a staff entwined by a serpent; adder's fangs; these paired fangs are folded back such a staff, of course, has remained a medical along the roof of the mouth when not in use. The emblem to the present day. fangs are erected as the snake strikes and, if they are Those who were gods, apparently, commonly had damaged, replacements are grown. Venom is pro- power over serpents, as was the case with Jupiter's duced by the snake's parotid glands; it should be son Hercules. Juno sent two to destroy him remembered that even very young adders can both when he was a child, but these were just seized in his prepare venom and bite and, further, several repeated two hands and crushed to death. Clearly snakes were bites, still involving significant volumes of venom, considered to have remarkable powers, yet they are possible from juveniles as well as adults. continued to be thought to have enigmatic qualities. In Britain, adders occur in Scotland, Wales and It is hardly surprising that in the Book of Genesis we England, being found on heaths and in woodland man or read that the serpent was '. . more subtil than any glades. Adders do not attack unless disturbed beast of the field .'; indeed, the serpent beguiled threatened. Such disturbance is often accidental, Eve and, as punishment, it was decreed for the snake when a person nearly steps on a snake or almost that 'upon thy belly thou shalt go, and dust shalt touches one when picking blackberries or wild thou eat . flowers. So, in an adder-infested area, it is sensible to While snakes have been revered in the past, many refrain from walking barefoot and to be vigilant when people appear to fear them now, perhaps instinctive- examining low vegetation. Nevertheless, vipers ly. In Britain, the only poisonous snake, the viper normally just writhe and slide away into cover when berus, is commonly chased and beaten to humans come towards them, especially whey they death, should one be discovered. In the same way, a are muscularly active after being warmed in the sun. harmless Natrix matrix is often killed by Should a person be bitten by a viper, it is better to people who imagine it to be dangerous to them or to stay still so that the toxin is not spread by muscle children; such people make no attempt to identify the contraction. The puncture marks of the fang tips will snake or even question whether it has a poison be visible and, as the venom has already been apparatus. injected and as the toxins are soon fixed in the It was observed that snakes sloughed their skins tissues, incision is not indicated and neither, in my and that the new skin, when revealed, was cleaner view, is the use of a tourniquet. It is the hand or foot and more brightly coloured than the old; the snake which is most commonly attacked but, while very moved off as though it had been re-born. The Roman unpleasant, a bite from an adder is rarely fatal in author Pliny maintained that a shed snake-skin was Britain; hypersensitivity to the horse serum of the helpful in labour, so during childbirth a sloughed is often a greater problem than the bite. skin was applied to the abdomen. It followed that For adder bites, it is probably unnecessary to use adder broth and flesh was prescribed as treatment in antiserum but, with severe venom reactions, steroids Britain for many illnesses during the Middle Ages are valuable. Hydrocortisone 100mg by injection a will and even up to Georgian times; if a snake shed its old should be given and broad-spectrum antibiotic skin and then glided off rapidly into cover then, help prevent secondary infection. Immunisation presumably, the had extraordinary abilities in against tetanus should be carried out, the method

74 Bristol Medico-Chirurgical Journal July 1985

depending on the immune state of the patient. from the females' anal glands; the pregnant females Snake-bite is a frightening event for most victims, give birth to their young in late August in Britain. hence it is advisable to give a sedative in addition to Vipers start to feed actively after they have moved analgesics as necessary. away from their hibernating areas, following skin Doctors know of the intense fear which many sloughing; common Lacerta vivipara, mice, People have of the snake and the snake-form, bank C/ethrionomys glareo/us, short-tailed Counting to a phobia in extreme cases. Some voles Microtus agrestis and young are all eaten. individuals, usually females in my experience, seem A viper will surprise and then bite a small ; in equally afraid of adders, grass snakes, slow- due course the venom takes effect and the Unguis fragilis, common eels Anguilla anguilla or dies. Detecting scent with its tongue, the viper will conger eels Conger conger. Doubtless there are follow the poisoned animal at leisure; often the prey sexually-based psychological explanations of the is swallowed in a hole or in thick undergrowth. condition, but I have not been impressed by the Vipers can propel themselves very quickly into her- results of psychoanalysis. Most patients are prepared bage if in danger, but they cannot keep up such a to continue to live with their snake phobia for, after speed for long; this is not surprising as the single all, town dwellers and even many country people do functioning lung is relatively small. Hence it is help- not encounter snakes at all frequently and most ful to the species that there is no need to rush when sufferers will agree that this is the case. in pursuit of poisoned prey. In late , adders One defence reaction of snakes, when cornered, is return to their hibernating areas, usually facing to the to hiss. Humans will hiss and boo at stage actors south, and most will disappear below ground during who do not come up to expectations and domestic October. eats will spit and hiss when in aggressive mood. Grass snakes, with distinctive yellow collars, are Then certain birds, notably geese, swans and owls larger than vipers and spend more time near water. hiss at aggressors, especially if their young are in They swim frequently and obtain much of their prey danger. Perhaps more significantly, several small in water; Rana temporaria, Triturus vul- cavity-nesting species will hiss at an intruder at garis and small fish are captured and swallowed. the nest-hole; as an example, a blue tit Parus caeru- Unlike vipers, grass snakes lay leathery-coated eggs feus will emit hissing noises should a wood from which their young are hatched. Eggs are laid in Apomedus sy/vaticus, for instance, disturb an in- moist, warm places where vegetation is rotting: a cubating bird. Snakes are enemies of mice and it compost heap is a favourite site. could well be that the evolution of a hiss by a bird Vipers and grass snakes are taken by other has protective value. Certain bird species, as well as in the wild although to what extent the potential mice, will avoid snakes if possible; this can be tested predators are bitten by adders is uncertain. Red foxes by displaying model snakes. Vu/pes vu/pes and badgers Me/es me/es will, at While the modern doctor is unlikely to prescribe times, eat both species; further, it is not uncommon adder broth for his patients, he may seek relaxation for dogs or cats to worry vipers and it is then that by observing vipers or grass snakes in their natural they get bitten. Presumably the same could happen . Vipers, with a dark zig-zag patterning down to adder-teasing foxes. I have seen a buzzard Buteo the back and an inverted V on the head, emerge from buteo carrying a snake in its talons and, by its large their hibernating holes in April; normally the pale size, this was probably a grass snake; I expect that males are seen first and the larger, red-brown females the bird-of-prey would have swooped down to come out one or two weeks later. Both sexes bask on secure the snake while it was sun-bathing. slopes in the available sun, but they are usually very Again, I once watched a kestrel Fatco tinnunculus wary of any human approach. Adders have no organ which was flying with a small, dark snake; it is likely of hearing as the tympanum is absent, but no doubt that this was a viper but whether the snake had been they detect ground vibrations which are transmitted killed already or whether it was poised to strike at the through the jaw bones. bird with its fangs to try to gain its release is an If suspicious and alerted, the adder protrudes and unanswered question. Maybe the snake's fangs flicks its forked tongue by which it senses the air and could not penetrate through the bird's feathers, but can detect the scent of an enemy; thus, if one is protection must depend on the total feather thick- 'ooking for adders, it is as well to take care that one's ness at the site of the strike. scent cannot be blown towards them. Moreover, It seems that the study of snakes, directly or vipers have effective vision by using their small eyes; indirectly, has much to interest the doctor. This the pupil is slit vertically, like that of a cat, and this applies in a limited way even in Britain where the Su9gests an adaptation to good vision in twilight or number of snake species is minimal and there is only as in the shade of herbage or hollow dens. one poisonous variety. But observation and in- After the males have shed their skins, mating vestigation of snake behaviour and biology is surely occurs, the males being attracted by pheromones important and much remains to be discovered.

75 Bristol Medico-Chirurgical Journal July 1985

Snakes are prominent in folklore and mythology; in when confronted suddenly with a snake. In the Book addition, the snake has significance in psychological of Numbers there is the passage: . . the Lord sent analysis and psychiatry. Furthermore, the complex fiery serpents among the people, and they bit the chemistry and pharmacology of snake venoms is a people many persons today must be happy that big and far-ranging subject; the varied compounds they do not live under those snake-infested con- are potent and could well yield drugs of future ditions. Further, I have no doubt that the doctors medical value, as well as continuing to make amongst them are grateful that snake-bite is a con- available substances with known therapeutic pro- dition which is not encountered often in Britain at perties and which require further assessment. the present time, especially as patients' eager friends Nonetheless, people who may have general agree- often bring along dead, aggressor snakes for ment with these views and who, seemingly, are inspection. entirely rational in their outlook, often become upset

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