CONTAGIOUS DISEASES IN EUROPEAN COUNTRIES.

GREAT BRITAIN.

SWINE FEVER IN 1895.

The records of the board of agriculture for Great Britain show that there were forwarded to the chief veterinary officer of that board, during the calendar year 1894, 12,054 sets of viscera for expert examination for swine fever. In 1895 the total number of sets of viscera forwarded to the same officer was 16,434, an increase over 1894 of 4,380 sets. The number of swine slaughtered in 1895 as diseased, or as a result of having been in contact or otherwise exposed to this infection, amounted to 69,931, and 10,917 more were reported as having died of the disease, making a total loss chargeable to swine fever of 80,848.

The disease was reported from 73 of the 96 counties of Great Britain. The losses in Scotland and Wales were not so great, comparatively, as in the rest of the United Kingdom. The number of hogs slaughtered in those countries was less than 5,000.

For several years a disease known by the term verrucose endocarditis was investigated in connection with swine fever. It was to a large extent coexistent with swine fever, and by many supposed to be a condition due to the fever. The search for indications of this disease was made with the 16,434 hearts submitted in 1895, and in 676 of these deposits were found; "and it is a very interesting fact in connection with these deposits that they are almost invariably found upon the valves of the right side of the heart." The examinations did not confirm the opinion that the disease was in any way related to swine fever.

The chief veterinary officer says:

On occasions when the circumstances have afforded a favorable opportunity for making an inquiry into the history of the animals affected with this disease, the veterinary surgeons who have forwarded the specimens have visited the farm or premises and invariably reported that the affected animals have remained in apparently good health until a short time prior to death; that the only deviations from health observed during life have been a certain amount of purple or red discoloration of the skin and a disinclination to feed, and that these symptoms have been immediately followed by all those distressing paroxysms which attend upon cases of angina pectoris, and death has quickly followed. In no instance has the same disease appeared among the other swine which had been kept in the same sty or in association with the diseased pig.

The following table, taken from the annual report of the board of agriculture for 1895, shows the number of cases of swine fever and diseased hearts detected in the post-mortems conducted in London:

Statement of post-mortems of swine in London in 1895.

A committee was appointed in 1895 to study swine fever in all its phases, and directed to report results to the board of agriculture. The inquiries instituted by this committee were extensive. A report was made in which it was asserted that the disease was due to a specific organism, a bacillus, which is capable of producing swine fever if introduced into the system of a healthy pig by feeding with cultures of the organism. This statement was founded upon the results of tests in which healthy swine were fed pure cultures of the bacillus obtained chiefly from the mesenteric glands of pigs affected with the disease. The report states that the bacillus causing swine fever is not sharply distinguished by its form, size, or staining reaction from many other organisms, and hence can not with ease be identified by microscopic examination.

Another committee was appointed in 1896 to carry on inquiries similar to those of the committee in 1895. Besides the information acquired by these two committees, the chief veterinary officer had experience extending over three years. All this is compiled and embodied in the report of the board of agriculture for 1896, and is deemed of such importance that it is reprinted here in full:

SWINE FEVER IN 1896.

After an experience extending over a period of three years, during which time the veterinary officers have made 40,000 post-mortem examinations of the viscera of pigs either affected with or suspected of swine fever, it is now proposed to place on record the results of the inquiries carried out by them, and of the two com

mittees which were appointed in the years 1895 and 1896 for the purpose of inquiring into the etiology and pathology of swine fever, and of those other diseases of swine which have been commonly regarded in this country as being either diagnostic of swine fever, or in some way due to that disease, namely, pneumonia in the pig, and verrucose endocarditis.

The remarks contained in this report will be confined solely to the knowledge which has been obtained of those diseases which have been found to exist in the pigs of this country, and have come directly under the notice of the board's veterinary officers. It is quite certain that the disease which exists among the swine in America, where it has received the name of hog cholera, is identical with our swine fever, because in the year 1879 some cargoes of pigs affected with hog cholera were landed at Liverpool, when an opportunity was afforded of identifying the lesions of that disease with swine fever.

To offer any observations on the etiology and pathology of the numerous diseases said to be of a contagious nature which are reported to exist among the swine on the Continent of Europe with a view to establish their identity with, or similarity to, swine fever of this country would serve no purpose, and with our imperfect knowledge of even the clinical features of those diseases it would be obviously injudicious to offer any remarks upon them.

HISTORY.

If the actual date and source when and whence swine fever originated can not be fixed, all the evidence at our command tends to the conviction that it must have been introduced from the Continent of Europe some time prior to the year 1858. No records appear to have been kept by the customs of the number of pigs imported before the year 1853, but a very large number were sent to this country during the period which followed, the number of pigs imported in the following years being 11,045 in 1854, 12,134 in 1855, 9,940 in 1856, 10,671 in 1857, 11,544 in 1858, 11,058 in 1859, 24,458 in 1860, 30,275 in 1861, and 18,132 in 1862. Nearly all these animals came from countries in which swine fever existed.

It is an admitted fact that prior to the erection of foreign animals' wharves the inspection carried out by the veterinary surgeons at the ports was of a very perfunctory character. The animals were brought in small steamers to certain wharves sanctioned by the customs for their landing; no sheds were set aside for their reception, but they were driven straight from the vessels into the adjacent streets where after a general inspection they were allowed to be removed either to the metropolitan market, which was then held at Smithfield, or elsewhere, the custom being to detain only the diseased or injured animals and to allow the others to be taken away.

Viewed in the light of our present knowledge of the difficulty which at times exists of detecting swine fever in the living animal, there can be no doubt that the disease was frequently introduced by means of foreign animals; and I have it on the authority of Mr. S. G. Holmans, the senior veterinary inspector of the board of agriculture for the port of London, who held the post of veterinary inspector to the customs in 1858, that soon after his appointment in that year he frequently found cases of "red soldier" (a name given to swine fever in the trade) among pigs imported from the Continent.

It is not, therefore, unreasonable to infer that prior to the year 1858 numbers of pigs affected with swine fever must have been landed in this country. The disease, however, was not likely at that time to spread rapidly, as for many years the majority of the pigs landed in London found their way to a firm of slaughterers who were in a large way of business at the East End. It must also be borne in mind that movement by rail at this period was expensive; and further, the demand for pigs in country districts was very limited. This combination of

circumstances would account for the disease spreading tardily into the interior of the country.

It was not until 1862 that the disease was discovered among home-bred pigs by Professor Simonds, who informs me that he first saw it on a farm belonging to a Mr. Cantrell, residing near Windsor.

Very soon after his visit to Mr. Cantrell's farm Professor Simonds heard of serious outbreaks in or near Somersetshire, and two years later (1864) Professor Brown witnessed an extensive outbreak at Buscot Park, in Berkshire, where he found on his arrival some 40 or 50 pigs dead and upward of 500 more either dying or in such a condition that they had to be killed by the owner.

It was in this year (1864) that Dr. Budd, an eminent physician residing at Bristol, became acquainted with the disease at the Clifton workhouse, and in the following year he brought the subject before the Royal Agricultural Society. Cases of the disease were also about this time seen by the late Prof. John Gamgee in Edinburgh. It is evident, therefore, that by 1864 the disease had become widely distributed in Great Britain.

From the year 1865, when the infectious nature of swine fever was first fully recognized, until 1878 it continued to spread in Great Britain and in Ireland unchecked, and with the increased facilities for movement by rail, it is not surprising to find that by the latter year it had been carried into nearly every county in England and into some of the counties of Scotland and Wales.

Prior to 1879 no returns were received by the privy council, swine fever not being included within the list of contagious diseases. There was, therefore, at that time no reliable information as to the extent of country then invaded. The veterinary officers of the board, who, prior to that date were acting as advisers to the privy council, had, however, long been familiar with the disease and from time to time became acquainted unofficially, through the members of the profession and agriculturists, with serious outbreaks and the losses incurred.

At the urgent request of some local authorities, more particularly Norfolk, swine fever was included in the list of contagious diseases at the end of the year 1878. Local authorities were given power to deal with the affection within their districts, and in subsequent years orders declaring infected areas and closing markets for the sale of pigs, except for slaughter, were issued by the privy council. It can not, however, be said that any results calculated to be of permanent good were derived from the measures adopted, inasmuch as the action of local authorities varied in proportion to the personal interest they took in the matter. In some of the urban districts the subject was regarded as of little or no importance, and in those rural districts where the losses were comparatively small, local authorities displayed no energy in its eradication.

It was not until November, 1893, that, at the urgent request of the agriculturists, the board of agriculture was called upon to make an attempt to stamp out the disease. No duty so difficult or troublesome had ever been imposed upon the veterinary department since it was created in 1865 for the purpose of stamping out cattle plague. This is evidenced by the fact that swine fever has never yet been eradicated from any country where it has once obtained a good foothold. From the foregoing history of swine fever in this country it will be observed that from 1858, at which time there is evidence that the disease was being introduced from abroad, until the year 1879, when it was first legislated for by the privy council, it was permitted to extend over Great Britain and Ireland without any attempt to check its progress, and that from 1879 until November, 1893, such measures as were adopted were of a varying and tentative character.

When it is taken into consideration that swine fever is a disease which combines with the fatality and contagious properties of cattle plague the occult nature of pleuro-pneumonia and is spread by pigs which, without being suspected of being diseased, are daily infecting the sties, soil, carts, trucks, and

markets in which they are placed, it can hardly be expected that, after having a widely spread existence throughout the country for a period of certainly not less than thirty years, it will be exterminated as rapidly as other contagious diseases of stock which have succumbed to what is termed the stamping-out process.

SYMPTOMS OF SWINE FEVER.

The clinical manifestations of swine fever have been so often and so fully described by various writers from the time when Dr. Budd wrote his treatise on the disease in the year 1865 that it would be unnecessary to repeat them if it were not for the fact that of late years it has become more and more evident that swine fever is not in all instances so extremely fatal a disease nor so easily recognized in the living animal as was formerly supposed.

The experimental work carried out by the departmental committee appointed in 1895-96, combined with the extraordinary opportunities which have lately been afforded the veterinary officers of the board of examining the lesions found in the viscera of pigs of all ages and sizes, have clearly established the fact that swine fever may assume two distinct forms, viz, the acute and fatal and the nonacute or slowly progressive.

In the acute form all those symptoms which are indicative of a severe febrile affection are present. The animals are disinclined to feed; they present evidence of great prostration and lie about their dwellings in a listless manner sheltering themselves from cold; their skins are hot, their eyes partially closed, and they are obviously suffering from some severe constitutional disturbance. Within a very few hours after these premonitory symptoms have set in the pigs become rapidly worse; they may or may not have a deep red blush on the skin, which is more particularly noticeable on those parts of the body where there is an absence of hair, such as the inside of the thighs, the point of the axilla, and over the abdomen. Choleraic evacuations, having a most offensive odor, succeeding upon constipation, follow later on, and the animals die perhaps as early as the third or fourth day after the symptoms have first been observed.

In some instances the disease proceeds with great rapidity through a herd, the symptoms being of a most aggravated and pronounced character, and the outbreak attended with great fatality.

Generally speaking, the above description depicts the symptoms of swine fever in the acute form, more especially when it breaks out in a herd of young pigs. In the nonacute form the disease progresses slowly, the clinical evidence is extremely obscure, the reddening of the skin, formerly regarded as being invariably present in swine fever, is absent, and beyond the fact that the animal is unthrifty, develops slowly, and perhaps has a constantly relaxed condition of the bowels, it may be asserted that there are no symptoms which could be regarded as absolutely indicative of swine fever, and nothing short of a post-mortem examination will enable even an expert to satisfy himself that the animal was affected with the disease.

As a general rule swine fever assumes this nonacute and slowly progressive form in pigs which have arrived at an age when their powers of resistance to disease are materially increased, i. e., in animals of eight or more months old; on post-mortem examination they are found to have been extensively diseased, more particularly in the large intestine, a portion of the digestive apparatus which does not appear to perform any very important function in connection with the nutrition of the animal, and so long as the stomach and small intestines remain healthy, pigs with a considerable amount of disease in the large intestine may still keep up their condition for a considerable time.