Anaesthetics used in experiments on animals / issued by The Research Defence Society.

  • Research Defence Society (Great Britain)
Date:
[1908?]
    ANAESTHETICS USED IN EXPERIMENTS ON . animals Ninety-six and a half per cent, of all expe^riments on animals in tliis country are inoculations, or of tlie nature of inoculations. For tliese inoculation-expeii- ments, aiisestlietics arc not used. But no cutting of any kind, more severe than the lancing of a superficial vein is allowed to be done, except on an animal under some anesthetic of sufficient power to prevent it feeling pain. There are three ways of preventing pain : (1) local anesthesia, by the use of cocaiii or eucain; (2) anesthesia by the use of such drugs as morphia or chloral; (3) anesthesia by the use of chloroform, ether, or nitrous oxide, (l) Local anesthesia is very seldom used in experiments on animals. Sir James Russell suggested to the Royal Commission that it might be used, under certificate A, before an inocula- tion ; “ More for the sake of the feelings of some experi- menters than for the needs of the animals. There are several experimenters who shrink from even the use of the hypodermic needle, and these are the very men who arc apt to transgress by using an anaesthetic.” That is to say, there have been cases where a licensee, making- inoculations under certificate A, which dispenses with the use of anaesthetics, has anaesthetised the animal to avoid the momentary pain of the introduction of the needle : for which purpose he ought to have held, not
    certificate A, but certificate B. But local ana3«t]iesia is not applicable to, and has never been employed in, experiments involving any sort of operation. (2) Morphia and chloral and urethane and similar drugs, to produce anaesthesia, must be given, and ar.e given, in large doses. “The question of complete aii£esthesia,” says Dr. Starling, Professor of Physiology at University College, “ will in each case be a question of the dose, whether you are dealing with chloroform or whether you are dealing with morphia. Morphia is a complete anaesthetic if it is given in large enough doses.” Not a month passes in this country without some person killing himself or herself with morphia or chloral. They die profoundly anaesthetised; they cannot be roused, or, if they outlast the morphia and recover, they remember nothing or next to nothing. “ My experience in this matter,” says Prof. Starling, “ would show that, after opium poisoning, if the patients have been saved, they are not conscious of the very strong shocks they have been given in order to try and hurt them while in that state of poisoning.” For the use of morphia and of chloral in experiments on animals, we have the following evidence given to the Commission:— Mr. Thane (Government Inspector).—Q. May I ask whether morphia is sometimes used on dogs as an anaesthetic, without chloroform or ether ? A. Morphia is very rarely used as an anaesthetic alone, that is quite certain. Q. You think that morphia could be adminis- tered so as to secure complete anaesthesia ? A Morphia can be administered so as to secure complete anaesthesia ; there is no question about it, but you probably would have to give a fatal dose. Q. You think that chloral and urethane would be effective ? A. 1 am quite sure
    that urethane would be. I have seen experiments with it. And I have no reason to doubt that chloral would be effective ; but I have not seen actual experiments under chloral. Dr. Schafer (Professor of Physiology at Edinburgh). —Q. Would you say that morphia only dulls pain, and does not remove it ? A. Certainly not. A sufficient dose of morphia absolutely removes all signs of pain. Sir T. Lauder Brunton.—Q. We have been told here repeatedly that morphia is not an anaesthetic ; that de- pends, of course, upon the quantity. We have been told also that chloral is not an anaesthetic; that also depends upon the quantity. These animals receive poisonous doses in order to completely narcotise them ? A. Yes; and as to the statements that chloral and opium or morphia are not narcotics, and do not remove pain, there is no other word for it, it is simply a lie; you may as well say that chloroform does not remove pain. If you give any animal a sufficiently large dose of chloral or opium, you so completely abolish sensibility that there is nothing you can do that will awaken its sensibility. The animal is as senseless as a piece of board. Mr. Henry Morris.—Q. Do you think that an animal, a dog or a cat, which receives a poisonous dose of morphia or opium, is in a condition to feel pain up to the time that death occurs ? .4. No, I do not think so. They suffer no pain. Q. We have been told here by several witnesses that opium is not an anyesthetic, and therefore, even when a poisonous dose is given, the animal is probably suffering tortures until death occurs. A. That is not so. Dr. Dixon (Professor of Materia Medica at King’s
    College). We do not use (or very rarely) morphin alone as an ansestlictic, not because it is not one, but l^ecause it leaves tlie motor cells active, and the animal is reflex. But it is quite commonly used for man now in Germany, when it is given with some drug which also paralyses the motor cells as well as the sensory; and so in Germany, and to a limited extent in England, it is given with hyoscin (the so-called morphia scopolamine narcosis) for operations where chloroform is deemed un- suitable. Dr. Dudley Buxton.—Q. In your opinion is morphia a complete anaesthetic? A. Quite. Q. For severe operations ? A. Certainly. Q. No pain would be present ? Not if you had a sufficient dose of it. As to the doses of morphia, chloral, and urethane, which are used in experiments on animals, we have Prof. Starling’s evidence. “ Urethane is used in man, as a simple narcotic, to produce sleep. A man weighing 50 kilos receives from one to five grammes ; to an animal, we give Ij- grammes per kilo, that is, about fifty times as much. AVe give that intravenously. AA^e first give what would induce anaesthesia in the ordinary way, namely, morphia and chloroform; then, if for some reason or other we do not want to go on with chloro- form, we should inject into the veins this very large dose of urethane. Or (if the high blood-pressure with urethane were a disadvantage) we might use chloral hydrate. In man, we give from 5 to 20 grains of chloral hydrate, that is, about 0’02 gramme per kilo. In the animal, we give gramme per kilo, that is fifty times as much, and then we get complete amesthesia. Then, again (if the vaso-motor action of chloral were a disadvantage), we have morphia. JMorphia is generally used as an adjunct to chloroform and ether. If the