Having regard to the number of animals killed by this evergreen, one might ask if its place in arboriculture could not well be taken by some equally beautiful and less deadly plant.
No season passes without fatalities to horses or cattle as the result of eating it. A tree may have been left untouched for years by animals pastured in its vicinity, until the stock-owner is lulled into a sense of security, and finally forgets its presence; or animals may be thought safe in a paddock, free from noxious plants, when a neighbour sets about lopping his overgrown yews, and the fatal branches fall within reach of animals, whose curiosity prompts them to eat the leaves. There is reason to believe that in certain conditions and circumstances yew may be partaken of with impunity, while at other times its effects are rapidly fatal. The green shoots have been experimentally fed to animals, and the results were very indefinite. If taken upon a full stomach, its toxic influence would seem to be more or less neutralized, while hungry animals have rapidly succumbed. Whether this latter result has come about from the larger quantity consumed, or from the empty state of the stomach, or from both causes combined, cannot be definitely stated.
Symptoms are those of a narcotic irritant poison. The animal is found dazed, and stumbles when made to move, falling down and showing the ordinary signs of intoxication. Respiration is shallow, the pulse oppressed, and the extremities are cold. Digestion would appear to be disordered or arrested, and, as a result, more or less tympany is present. Post-mortem examination is satisfactory only in so far that it reveals the presence of twigs and leaves of the plant; there is, however, invariably more or less congestion of the stomach and bowels, sometimes more especially marked in the former, at others in the latter. Beyond this there is seldom any noticeable change referable to the poison.
Fig. 453. - Yew (Taxus baccata).
No direct antidote is known, but the symptoms of collapse may be combated by diffusible stimulants, as alcohol and ammonia, while friction to the skin, bandages to the legs, clothing to the body, and every effort to restore the circulation should be attempted.
An aperient is essential to get rid as quickly as may be of any portions of undigested poison, linseed- or castor-oil being the most suitable.
Liability for yew poisoning has been tested in the High Court of Justice, and Mr. Justice Charles decided that it is the business of an owner to prevent his animals from eating yew when growing on a neighbour's land.