Popular Science Monthly/Volume 86/January 1915/What Animal Experimentation Has Done for Children




THE rich contribution that animal experimentation has yielded to the direct, curative treatment of disease is well known to all educated physicians. The lay public, however, seem to be insufficiently informed as to the many benefits that have been derived from this method of scientific investigation. If so, they would give little heed to the false statements and hysterical imaginings that are periodically given out by small but vociferous opponents of this beneficent work. If the public once clearly understands that helpless, suffering children will be the class to suffer most, a positive and instant check will be administered to those who aim to stop the most fruitful advance in scientific medicine. At present, a few ill-balanced people seem to derive a cheap and easy glow of self-satisfied altruism by exaggerating the discomforts of animals who are being studied for the good of the human race.

The object of this paper is to show what animal experimentation has actually done for children. Let us substitute real facts for morbid and exaggerated fancies. Let us weigh the relative importance of a child's suffering or life against the discomfort and even occasional suffering of a dog. This is directly pertinent, for, in a last analysis, the defenceless child will have to pay the principal penalty if the advances in treatment brought about by animal experimentation are to be retarded or checked. A large part of all sickness occurs among children. The period of growth is one of great physiological energy, and pathological changes are often only an index of an overstrained physiological activity. Besides this, young protoplasm is irritable and favors the development of germs of all kinds. The victims of microbic diseases are chiefly the young. It is evident that the complete understanding and treatment of disease at this period assume the greatest importance, and anything interfering with such beneficent work may have the gravest consequences. It thus becomes a question of morals as well as medicine.

A brief review of some of its brilliant accomplishments will serve to emphasize the value of animal experimentation for children:


The most overwhelming proof of the value of a specific treatment is seen in connection with antitoxin in diphtheria. Before the introduction and use of antitoxin in 1895, diphtheria could truthfully be called one of the greatest scourges of childhood. The death rate began to fall all over the civilized world with its increasing employment.

The following table, quoted from Keen, gives the official reports of the mortality from diphtheria for every 100,000 inhabitants in certain American and European cities before the use of antitoxin and after its employment had become general:

Table of Mortality from Diphtheria
Per 100,000 Inhabitants
1894 1905
New York (Manhattan) 158 38
Philadelphia 128 32
Baltimore 50 20
Boston 180 22
Brooklyn 173 43
Pittsburgh 64 26
London 66 12 .2
Paris 40 6
Vienna 114 19

Later on, Dr. Park in a study of the average death rate from diphtheria in 19 large cities of the world in 1893 shows it to have been slightly over 80 per 100,000; in 1895, when the antitoxin treatment was introduced it began to fall, and by 1907, when antitoxin was generally employed, the rate had dropped to 17 per 100,000.

In the London hospitals the mortality has been reduced from 29 per cent, to about 10 per cent. The same is true of other large hospitals of the world.

These studies extending over widely diverse localities and long periods of time do away with such possible errors as varying severities of epidemics or chance local conditions.

Not only has the death rate been much lowered, but the severity of the disease and its complications have been marvellously changed for the better. Perhaps this is best seen in the great diminution of the fatal and agonizing croup cases, where the false membrane descends into the windpipe and causes death by slow strangulation. We wish those who are trying to throttle scientific research would witness the awful struggle of a child dying from diphtheritic croup. Fortunately even physicians are now seldom forced to go through such an ordeal, owing to the beneficent results of a treatment directly inaugurated as a result of animal research. At the Willard Parker Hospital, even the late and neglected cases of croup that have not had the remedy before admission, after a large, though belated dose of antitoxin now very rarely die from strangulation. If they succumb to other complications, they are at least mercifully spared the torture of prolonged strangling. Before antitoxin days, two thirds of the croup cases that were tubed died at this hospital; now three quarters are saved. It is hard to realize what such figures actually mean. In the years preceding the discovery of the germ that causes diphtheria and the working out of its antidote, among the cases reported as dying from diphtheria, more than 75 per cent, were attributed to diphtheria of the windpipe.

Antitoxin, when early and properly given, will not only cure in a majority of cases but likewise immunize those closely exposed to the infection of the disease. Over 35,000 cases were thus treated by the New York Board of Health without any serious sequel.

Cerebro-Spinal Meningitis

One of the most fatal and distressing diseases, confined largely to children, is epidemic and sporadic cerebro-spinal meningitis. Before the working out of the anti-meningitis serum by careful, scientific experimentation on animals, there was no method of preventing the growth, and appalling effects of the meningococci that caused the disease. Now we have a serum that not only directly destroys or inhibits the growth of the germs, but also indirectly acts by stimulating the white blood cells to overcome the germs. At the same time a neutralizing action is exerted on the soluble and diffusible poisons that are secreted by the deadly meningococci. As a result, not only has the mortality been greatly lowered, but the severe symptoms and crippling complications have been most favorably influenced. The lowest mortality before the serum treatment ran from about 50 per cent, in sporadic cases to 75 per cent, in the epidemic form in different parts of the world. When the serum is now given by spinal puncture, the mortality drops to about 25 per cent, or even lower. If the serum is given early in the disease, the altered mortality is still more remarkable. The following table quoted by Dunn from the studies of Dopter shows this feature:

Mortality in Epidemic Meningitis under Serum Treatment

Cases Analyzed According to Period of Injection

Per Cent.
Per Cent.
Per Cent.
First to third day 14.9 7.14 8.2
Fourth to seventh day 22.0 11.1  14.4
Later than seventh day 36.4 23.5  24.1

In cases that recover, the serum treatment not only shortens the duration of the disease—sometimes by several weeks—but lessens the chances of the terribly destructive sequelæ, such as hydrocephalus, blindness and deafness.


While tuberculosis is a disease of all ages, its ravages are peculiar and widespread at the beginning of life. Children contribute their fair share of the awful record of one seventh of all the deaths in the world. Certain peculiarities of tuberculous manifestations in early life, such as the special involvement of lymph glands, bones, joints and peritoneum, rather than a limitation to the lung, have made the disease an interesting and hopeful study at this time. In order to successfully treat the condition, early recognition, before much destruction of tissue has taken place, is imperative. Early diagnosis, by means of inoculation, means a successful cure in a large proportion of cases. Hump-backed children, from tuberculosis of the spine, and permanent lameness from hip-joint disease, are rapidly becoming misfortunes of the past. Not only the way in which tubercle bacilli act in various tissues, but the methods of their transmission, are now known, thanks to animal experimentation. The knowledge of its spread by meat and milk has led to careful inspection of carcasses and an improvement and cleaning up of the milk supply in large areas of country by commissions and municipalities. The whole tuberculosis crusade, in which children are so largely the beneficiaries, would have been impossible without the use of rabbits and guinea pigs. The communicability of tuberculosis has thus been proven and efficient steps taken to prevent its spread. The treatment by abundant fresh air, sunlight and forced nutrition has naturally followed a better understanding of the disease. Seaside and mountain sanitoria, that are now so successfully treating the various forms of bone and gland tuberculosis in children, are but the end products of demonstrations that started in animal experimentation. Trudeau with his series of inoculated rabbits, keeping some in the open air with full nourishment that recovered, while those that were confined and underfed died, started the ideas that have had such fruitful results. In a period of twenty years, the death rate from tuberculosis in New York was reduced approximately forty per cent., and in Boston fifty-five per cent. This means the escape of hundreds of children from death or permanent disability.

Finally, a most hopeful result of animal study has shown that tuberculosis is not inherited. Thus has been removed the hopelessness that went with such a belief as regards the child. A knowledge that this dreaded disease is usually preventable and often curable acts as a stimulus to renewed and successful efforts for its final elimination.


The scant relief possible for most forms of idiocy is well known to both physicians and teachers. In recent years one kind of mental defect has been explained and largely cured by a knowledge of the internal secretion of the thyroid gland. Formerly these cases were doomed to remain semi-imbeciles. They were repulsive in appearance, with stunted growth, facial blankness, tongue protruding from half-open mouth, trunk large with pendulous abdomen and short stumpy limbs. A dull, apathetic mentality was always in evidence. An implantation of the thryoid in the abdominal cavity of dogs by Schiff showed that this gland would functionate even after its removal or absence from its normal location. From this it was but a step to demonstrate that by administering an extract of the thyroid gland by the mouth, the symptoms due to its abnormal absence in the child would be removed. The arrested, perverted growth and mental dulness due directly to the absence of this important internal secretion can thus be easily corrected by giving the dry extract from the thyroid of an animal. A whole class of hopeless defectives has thus been rehabilitated.


This fearful disease, produced by the bite of a rabid animal, is one to which children are peculiarly disposed on account of their close association with domestic animals and their lack of judgment in failing to recognize sickness or distemper among them. Just here can well be shown the disastrous results of some of the efforts of those peculiar people who suffer from "Zoophil psychosis." According to Frothingham there were but 38 rabid dogs in England in 1892, but at this time the authorities removed the "cruel muzzle" owing to an agitation by the "dog lovers." As a result, during the next five years 1,602 dogs, as well as many other animals, and 51 human beings died from this agonizing disease. Even if proper means of prevention are not enforced and individuals are bitten by rabid animals, the mortality can now be very largely reduced. The Pasteur treatment has already lowered the death rate from between 6 per cent, and 14 per cent, to well under 1 per cent. This is true all over the world. Even the dogs, as well as children and adults, have profited by Pasteur's efforts at stamping out hydrophobia.


The prevention and change in the severity of small-pox by vaccination have been of largest benefit to children, as this loathesome disease is especially fatal and disfiguring at this time. Of 3,164 deaths in the great Montreal epidemic, 85 per cent, were in children under ten years. When vaccination is performed in infancy, the disease is prevented during the period of growth or so altered as to be innocuous. Early vaccination has completely changed the character and age period of smallpox: it was formerly so essentially a child's disease as to be called "child pox." Rotch reports that during fifteen years no deaths from smallpox occurred in Boston in children who had been vaccinated under five years of age, while during the same time the mortality in the unvaccinated was 75 per cent. Similar conditions have been noted in other centers. It is hard to realize what overwhelming calamities were once caused by this fearful disease. Smallpox has now been practically stamped out in civilized countries by vaccination, yet it has been estimated that 60,000,000 died from this loathsome affection in Europe during the eighteenth century, and multitudes who did not die were permanently scarred and mutilated. The reign of destruction and death accompanying this disease continued until Jenner’s great discovery in 1796. In Germany, where a compulsory vaccination and re-vaccination law has been enforced, there has not been an epidemic of small-pox for thirty-five years, although adjacent countries, not so protected, have had numbers of epidemics.

In the present discussion, it is interesting to note that a lower death rate from small-pox has been largely confined to children as they are so generally vaccinated. After the first decade, the protection is apt to wane and revaccination is required for full safety. The last objection to vaccination—the possible induction of other diseases—has now been completely removed by experiments on calves which shows that smallpox virus may be converted into a protective but innocuous vaccine virus by being transmitted through several bovine generations. Calf vaccination thus provides an adequate amount of virus that is safe because produced under careful scientific oversight of an animal fully protected from any disease or outside contamination.

While in the above-mentioned diseases the preponderating benefits in treatment have accrued to children, there are others in which the child shares with the adult in the advances derived from animal experimentation.


Malaria, to which children are very susceptible, has been made largely a preventable disease by a study of the mosquito carrier, its breeding places and natural history, and by inoculation experiments on animals and man. It was proven by Italian observers that the mosquito disseminates bird malaria in the same manner as in the human subject. The final upshot of these investigations has been that large tracts of hitherto waste and dangerous land have been rendered safe and productive. A widespread cause of debilitating sickness, and even of death, has thus been removed. In such areas, the saddest sight has been the stunted, anemic children, with enlarged livers and spleens, the evidences of chronic malarial poisoning that can now be obviated by putting modern knowledge into effect.

The benefits of vaccination against typhoid fever are shared by children with adults, and the tests for the speedy recognition of tuberculosis and syphilis have given brilliant results by allowing early and successful treatment. It has been ignorantly or maliciously stated that these diseases may be induced by these tests, whereas such an accident is rendered impossible by the preliminary destruction of the living virus. Most of these charges are made by those having a ludicrous ignorance of the most elementary facts of biology.

In many cases, the destructive and prolonged poisoning of syphilis can be eradicated by a few doses of Salvarsan followed by the older alterative treatment, and thereby a hereditary taint completely removed. It is thus possible to protect innocent mothers and unborn or recently born infants.

Surgical Conditions

It is hardly necessary to state that children have derived their full share in the inestimable benefits that have followed aseptic and antiseptic surgery. Septicemia and pyemia are prevented and frequently cured. Cavities of the body formerly out of reach of surgical aid are now fearlessly explored and life thus saved. As an example, the various obstructions of the bowel peculiar to children are cured in a large proportions of cases. In former times death usually ensued in such conditions, as both physician and surgeon feared the large mortality that followed the opening of the abdomen. Even very young infants are now successfully operated upon for this grave condition. Certain forms of peritonitis are cured by simply opening the abdomen.

Recently, bone grafting, that promises brilliant results in straightening crooked backs and other bony deformities in children, has been successfully tried as a result of previous experiments on animals.

Profuse and uncontrollable hemorrhages in the newly-born, formerly fatal, are now saved by transfusion, which was first studied and the technique perfected by vessel suturing in the lower animals. Practically the whole realm of surgical accidents and diseases in children has been benefited and illuminated, directly and indirectly, as a result of animal experimentation. We must not forget to mention, in this connection, how anti-tetanus serum has prevented lockjaw after certain jagged wounds. It has thus helped to take away some of the horror from the frequent accidents to children in the cherished, but undesirable, Fourth of July celebrations.

If such great and beneficent work has already been accomplished in a few years, it is safe to prophesy more certain and brilliant results in the future. Scientific men have perfected their knowledge and technique and are fast conquering nature's secrets. There is no foretelling to what extent disease can be overcome by persisting in the present fruitful methods. Already infantile paralysis is being hopefully studied as to cause and consequent cure. The same can be said of other crippling and fatal diseases.

The lay public must be taught to appreciate and encourage the devoted men who are patiently toiling in laboratory and clinic, frequently at the risk of their own health or life, to discover the secrets of disease and thereby conserve both health and life in others. They are the true apostles of the modern world. Our civilization owes them a debt of gratitude that can never be paid. If they are to be harried and obstructed in their fruitful work, it will be at the risk of ending all scientific advance. Any community with such narrow vision as to allow such obstruction will stand convicted by the judgment of an enlightened humanity.