PLATE XXXIII.PLATE XXXIII.FOOT-AND-MOUTH DISEASE.(Click to enlarge)
The disease in other countries.—Foot-and-mouth disease has prevailed in Europe for a great many years and has occasioned tremendous economic losses there.
In Italy, France, Switzerland, Germany, and Russia the plague has existed so long and has gained such a foothold that it is economically impossible to fight it with the American methods of slaughter and disinfection, for to do so would kill a large percentage of the live stock of those countries. In consequence, little or no progress toward eradication has been made by the authorities, though the severity of the disease in France appears to have abated somewhat in recent months.
The outbreak which appeared in Germany in 1888 increased steadily until 1892, when it diminished gradually for a few years, but the disease again reached great proportions in 1899. Thereafter it continued to exist to a greater or less extent until in 1911 it attained a virulence unequaled before. In that year 3,366,369 cattle, 1,602,927 sheep, 2,555,371 hogs, and 53,674 goats were affected. At that time the total number of cattle, sheep, swine, and goats in Germany was only 51,319,000, while there were in the United States 172,572,000, or between three and four times as many. It can readily be imagined, therefore, what it would mean to the United States if the disease were to gain the foothold here that it had in Germany, where, as these figures show, approximately one out of seven of the animals susceptible to the disease was affected.
The German Government, of course, has not left the disease to itself. It attempted to control some outbreaks by the method of slaughter, but the pestilence had gained too much headway and was too firmly established in too many portions of the country for this method to succeed, and the slaughter of the infected herds had to be abandoned. It now appears that there is no hope of getting rid of it until the virus has worn itself out. As soon as the animals' period of acquired immunity is over and favorable conditions present themselves, the contagion breaks out with renewed virulence. It has been impossible to control it by means of quarantines. One scientist has asserted that unless all the infected farms were absolutely isolated and the movement, not only of live stock but of persons, absolutely prohibited, the disease could not be stamped out. Such a quarantine is, of course, utterly impossible to enforce. In portions of Germany the farmers, realizing that the disease is inevitable, make haste to be done with it by exposing their stock deliberately to mild cases in the hope that this will result in an immediate, mild attack and immunity for several years thereafter. Such immunity, however, is very uncertain.
Great Britain, Denmark, Norway, and Sweden, on account of their comparatively isolated positions, have been more successful in keeping out the disease. The outbreaks in those countries have been more sporadic, and by resorting to immediate slaughter the authorities have been able to stamp them out. Great Britain has applied both quarantine and slaughter for many years, and in an outbreak near Dublin in 1912 measures were adopted which were even more stringent than any that have been used in the United States. A British official (Cope) asserted in 1899 that after his country's experience with this disease it was "more dreaded by the farmers and stock raisers of Great Britain than cattle plague or pleuropneumonia, and they are now willing and ready to put up with any restrictions, of however drastic a character, considered necessary by the central department to stamp it out." The British authorities have succeeded in suppressing each outbreak, but reinfection often occurs from the neighboring continent. At the present time (April, 1922) Great Britain is having a siege of the disease, but is applying vigorous measures for its suppression.
In November, 1906, the disease reached Belgium from France, where it was quite prevalent, and by the end of the year every Province in Belgium was affected, and the Netherlands as well. Efforts to eradicate it from Belgium were unavailing. The Netherlands apparently succeeded in stamping it out for about six months, but it reappeared there.
The disease is also more or less prevalent in Central Europe, Spain, and in the Balkan countries.
Australia and New Zealand have remained free from it.
We have less accurate information regarding Asia and Africa, but the disease is known to prevail in Japan and China and in the Philippine Islands, and it is doubtful whether any considerable part of the Orient is free from it.
In South America it is reported as common in Brazil, Argentina, and Uruguay, and it probably exists in other countries.
Canada and Mexico are fortunately free from the disease.
Outbreaks in the United States.—Foot-and-mouth disease has appeared in the United States on six different occasions—1870, 1880, 1884, 1902, 1908, and 1914.
An extensive outbreak in 1870 was introduced by way of Canada, where the infection was brought by an importation of cattle from Scotland. It spread into the New England States and New York and appears to have been arrested within a few months. Its failure to spread more extensively and its early disappearancehave been ascribed to favorable conditions, such as the movement of live stock from west to east, the limited trading at that period as compared with the present time, the restriction of traffic by winter weather, and the infrequency of travel which obtained at that time among people.
About 1880 two or three lots of animals affected by this disease were brought to the United States, but there was no extension from the animals originally affected.
In 1884, at Portland, Me., there was a small outbreak caused by imported cattle, and the disease spread to a few herds outside the quarantine station. Owing to the small number of animals affected and the limited area of territory covered by the disease, it was easily controlled by the ordinary measures of quarantine and disinfection.
It will be observed that in all these early outbreaks the contagion was introduced with imported animals. Since the development of a stringent system of inspection and quarantine of imported live stock, no instance of that kind has occurred. On subsequent occasions the infection has evidently been brought in with contaminated products or materials and not by means of live animals.
In November, 1902, the disease was discovered in Massachusetts and Rhode Island. The earliest cases were traced to Chelsea, Mass., near the docks, and it was suspected for a time that the infection was brought in with foreign shipping, by some such means as hay, straw, halters, ropes, hides, hair, wool, etc. Later developments, however, and especially investigations into the cause of the 1908 outbreak, led to the belief that a more probable source of the infection was cowpox vaccine virus imported from a country (probably Japan) where foot-and-mouth disease existed, the vaccine virus being contaminated with the virus of foot-and-mouth disease.
A Federal quarantine was declared by the Secretary of Agriculture on November 27, 1902, as soon as the nature of the disease was established, and steps for eradication were at once taken by the Bureau of Animal Industry of the United States Department of Agriculture in cooperation with authorities of the affected States. The methods followed consisted of inspection to trace and detect the disease, quarantine of infected premises and territory, slaughter and burial or burning of diseased and exposed animals, and disinfection of premises.
This outbreak involved Massachusetts, New Hampshire, Vermont, and Rhode Island, and was eradicated in about six months. Two hundred and forty-four herds, including 4,712 cattle, were found infected. Of these, 205 herds with 3,872 cattle, as well as 360 hogs and 220 sheep and goats, were slaughtered. The cattle infected but not slaughtered were those that either died or completely recovered before slaughtering could be carried out. The animals slaughtered were valued at $184,155.10, and the Federal Government reimbursedowners to the extent of 70 per cent, or $128,908.57. It is understood that the States paid the remainder. The total cost to the Department of Agriculture of stamping out the disease was about $300,000.
The next appearance of the foot-and-mouth disease was early in November, 1908, when it was observed in cattle near Danville, Pa. A Federal quarantine was issued November 12. The infection was traced back to the stockyards at East Buffalo, N. Y., and to Detroit, Mich. The disease appeared in the States of Michigan, New York, Pennsylvania, and Maryland. A careful and thorough investigation made by Mohler of the Bureau of Animal Industry and Rosenau of the Public Health Service demonstrated that the outbreak started from calves used to propagate vaccine virus at an establishment near Detroit, and that the source of the infection was contaminated Japanese vaccine virus.
Vigorous measures of eradication similar to those employed in 1902-3 were at once put into effect and the disease was stamped out in about five months at an expense of about $300,000 to the Department of Agriculture, and of about $113,000 to the States. The inspectors made 108,683 visits to farms, stockyards, etc., and inspected more than 1,500,000 animals (including reinspections). One hundred and fifty-seven premises were found infected, and 3,636 animals (2,025 cattle, 1,329 hogs, and 282 sheep and goats), valued at $90,033.18, were slaughtered. Owners were reimbursed for the value of their animals and property destroyed, one-third being paid by the States and two-thirds by the Federal Government.
The latest invasion was discovered in the vicinity of Niles, Mich., in October, 1914, after it had evidently been under way since August of the same year. This is the most serious and extensive outbreak ever known in this country. The disease extended to 22 States and the District of Columbia, at places ranging from the Atlantic to the Pacific coasts. The work of eradication was not completed for more than a year. The affected States were Connecticut, Delaware, Illinois, Indiana, Iowa, Kansas, Kentucky, Maryland, Massachusetts, Michigan, Minnesota, Montana, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Virginia, Washington, West Virginia, and Wisconsin. Illinois had the largest infected area and the largest number of animals affected. The Union Stock Yards at Chicago became infected and were a source of dissemination of the contagion north, east, south, and west. These and other yards found infected were closed temporarily and disinfected.
The first Federal quarantine was issued October 19, 1914. A campaign to check the spread of the disease and to stamp it out was immediately begun by the United States Department of Agriculture in cooperation with the State authorities. Quarantines against the movement of animals and certain materials from the infected areaswere declared, shipments were traced, rumors investigated, and thorough inspections made in an effort to discover all infected stock. As measures of eradication, diseased herds were slaughtered and buried and the premises disinfected. The owners of live stock and other property destroyed on account of the disease were reimbursed to the extent of the appraised value, half of which is paid by the Federal Government and half by the State. There were slaughtered 172,720 animals (76,575 cattle, 86,492 swine, 9,511 sheep, 133 goats, and 9 deer), in 3,482 herds. The total appraised value of these animals was more than $5,800,000. The expense to the Federal Government of eradicating this outbreak was about $4,540,000.
Symptoms.—In three to six days, or even longer, after the exposure of the animal to the infection the disease makes its appearance. It is usually first indicated by the animal suffering from a chill, quickly followed by an invasion of fever, which may cause the temperature to rise as high as 106° F. These symptoms are not always present, or may be in so slight a form as to escape notice. Following this in one or two days it will be noticed that small vesicles or blisters about the size of hempseeds or peas are making their appearance upon the mucous membranes of the mouth at the border and upper surface of the tongue near the tip, the inside of the cheeks, on the gums and the inner surface of the lips, or on the margin of the dental pad. These little blisters contain a yellowish, watery fluid and gradually become more extensive as the disease advances. Soon after the eruptions have appeared in the mouth of the animal considerable swelling, redness, and tenderness will be noticed about the feet, at the coronet, and between the digits of each foot. A day or two later eruptions similar to those within the mouth make their appearance upon these swollen regions of the foot, and at this stage it is usual to find that like lesions have made their appearance upon the perineum of the victim. In the case of milk cows the udder, and more particularly the teats, show the same vesicular eruption, but the latter as the result of milking soon become covered with reddened spots deprived of the superficial layer of skin and may develop deep, obstinate fissures.
As soon as the disease has become well established the patient evinces pain when attempting to eat; in fact, the appetite is often so seriously affected that all feed is refused, and the animal uneasily opens and shuts its mouth with a characteristic smacking sound, while strings of cohesive, ropy saliva hang suspended from the lips. With the advance of the disease the vesicles widen and extend until they may reach a diameter ranging from that of a dime to that of a silver dollar. These rupture soon after their appearance, sometimes on the first day, more rarely on the second or third day. After they have ruptured, the grayish-white membrane forming the blistermay remain attached for a day or more, or disappear speedily and leave deeply reddened, sensitive spots or erosions, both within the mouth and upon the coronet and between the claws of the feet. Similar erosions, which quickly form scabs, as a rule, may be noticed in cases in which the teats of milk cows have become affected, and instances are reported in which sloughing of the tegument immediately around the lesions upon the udder has occurred. Owing to the tough, fibrous nature of the bovine skin, it is exceedingly rare for sloughing to occur upon any part of the body other than those mentioned.
The attack upon the feet of an animal is frequently manifested in all four feet at once, but one or more of the feet may entirely escape and remain unaffected throughout the course of the disease. The ulceration of the interdigital tissue may extend to the ligaments of the fetlock or produce disease of the joint or bone. As the feet become sensitive and sore the animal persistently lies down, and it has been found that bedsores develop with amazing rapidity in all such cases and wholly baffle all attempts at treatment until after the patient has regained its feet.
The disease may attack some of the internal organs before it appears upon any of the external tissues. These cases are very liable to prove quickly fatal. The animal dies from paralysis of the heart, due to the formation of poisonous principles within the system; it may suffocate by reason of the action of these same poisons upon the tissues of the lungs, or it may choke to death as a result of paralysis of the throat.
In cases of serious affection of the udder the erosions will often be found within the passages of the teats, resulting in a "caked" udder, and the same toxic poisoning which is the cause of death in the apoplectiform types just mentioned may arise from this source. In any event the milk from such cases is dangerous for use, causing fatal diarrhea in sucking calves or young pigs and serious illness in human consumers. The milk obtained from cows suffering with foot-and-mouth disease is not readily converted into either butter or cheese, but remains thick, slimy, and inert in spite of churning and attempts at curdling. Pregnant animals may abort. In pigs, sheep, and goats the lesions in the foot are most common, but both forms may be observed or only the mouth lesions.
When the disease has become fully established it will be found that the duration of the attack will vary greatly with different animals. From 10 to 20 days are usually required for the recovery of the normal appetite and spirits in mild outbreaks, while the return to a full flow of milk, in the case of milk cows, seldom occurs before the arrival of the following season.
In the malignant type of the disease it requires from three months to a year for an animal to recover. The mortality, as already stated, is usually low. The disease is more fatal in young animals that have been fed on infected milk, and produces death in from 60 to 80 per cent of these cases as a result of gastroenteritis. In the 1914 outbreak numerous new centers of infection started among hogs and calves which were fed on unpasteurized, infected milk from creameries.
Diagnosis.—The recognition of this affection should not, as a rule, be difficult, especially when the disease is known to be in the vicinity; in fact, the group of symptoms form a clinical picture too decided to be doubted. The combination of high fever, vesicular inflammation of the mouth, and hot, painful, swollen condition of the feet, followed 24 to 48 hours later by the appearance of numerous blisters varying in size from that of a pea to that of a walnut on the udder and feet and in the mouth should prevent any serious or long-continued error in the diagnosis; however, in the inoculation of calves we have a certain and final test. In 24 to 96 hours after inoculation the calves present the characteristic blisters. Such inoculation should be practiced, however, only by officials properly authorized to deal with contagious diseases.
Differential diagnosis.—The lesions of no other disease of cattle closely simulate the vesicular eruption of foot-and-mouth disease on the lining membrane of the mouth. When the blisters have ruptured, however, and the resulting lesions have become contaminated by numerous secondary forms of microorganisms, the correct recognition of the disease may be involved in considerable difficulty.
Cowpox or horsepox may be accidentally transmitted by inoculation. But the eruption of the "pox" goes on to the development of a pustule, while in foot-and-mouth disease the eruption is never more than a vesicle, even though the contained fluid may become turbid. The inoculation test in the case of cowpox does not respond with fever and eruption for at least 10 days, and often longer.
Necrotic stomatitis (sore mouth due to a germ) may be distinguished from foot-and-mouth disease by the fact that in the latter there is a rapid infection of the entire herd, including the adult cattle, as well as the infection of hogs and sheep. The characteristic lesion of foot-and-mouth disease is the appearance of blisters containing a serous fluid upon the mucous membrane of the mouth and upon the udder, teats, and feet of the affected animals. In necrotic stomatitis blisters are never formed, destruction of the tissues occurring from the beginning and being followed by the formation of yellowish, cheesy patches, principally found involving the lining membrane of the mouth, especially the tongue and cheeks.
In mycotic stomatitis (sore mouth due to a fungus or mold), portions of the lining membrane become inflamed and in a few days itchanges to a croupous membrane which peels off, leaving a raw surface, while the thin skin between the toes may also be inflamed. The previous history of the case; the failure of the blisters, if any appear, to spread extensively; the absence of vesicular eruptions on other portions of the body, notably the udder and teats, and, characteristically, the hoof, together with the absence of rapid spread to practically all cattle in the herd and the complete negative character of inoculation of calves, distinguish between the local disease named and foot-and-mouth disease. Mycotic stomatitis occurs in only from 10 to 50 per cent of the animals in a herd, usually in the late summer or early fall after a dry spell, and it does not run a regular course.
The lesion, resulting from ergotism may be distinguished from those of foot-and-mouth disease by the lack of eruptions in the mouth and by the location of the disease at the tips of the ears, end of the tail, or upon the lower part of the legs, usually below the knees or hocks. The lesion of ergotism does not take the form of pustules or blisters, but manifests itself first as a swelling about the ankle, which later may slough and circumscribe the limb, forming a deep crack, extending entirely around the limb and forming a distinct line of demarcation between the healthy skin above and the diseased below. The absence of ulcerous sores on the coronet and between the claws, together with the healthy condition of the membranes of the mouth and the knowledge that the lesion upon the limb in question extends uninterruptedly around it, should point conclusively to a diagnosis of ergotism and to the exclusion of all fears of foot-and-mouth disease.
In foul foot or ground itch of cattle, the inflammation of the skin and toes is general and not in certain spots, as in foot-and-mouth disease. The mouth remains unaffected, and the presence of the disease may be traced to filth and poor drainage.
The severer forms of the disease might be confounded with certain general diseases. If gastrointestinal symptoms predominate, acute gastric catarrh or inflammation of the intestines might be thought of. Involvement of the lungs may lead to a diagnosis of acute congestion of the lungs or pneumonia. The distinction is apparent in these diseases by the lack of vesicular eruption on the mucous membrane or skin, and also by lack of evidences of infection in the herd or neighboring animals.
Prevention and eradication.—The measures to be adopted to prevent the spread of the affection must take into consideration the highly infectious nature of the disease, its ease of dissemination, and the liability of the virus to live for long periods outside the body of an animal. Great care should therefore be observed in keeping healthy animals unexposed to the contagion. When an outbreak occurs in a community the owner should make every effort to keep other animals from coming in contact with his diseased cattle. Thisespecially applies to dogs, cats, goats, and poultry, which usually have access to the stables and barnyards and in this way furnish excellent means for disseminating the infectious principle. He should be equally particular in prohibiting any person from coming onto his premises, especially an attendant or owner or other person in any way connected with cattle. Such a herd may be placed under quarantine, with an inspector appointed to keep the premises under constant surveillance.
This method of quarantine alone, while very satisfactory in many instances, is rather tardy in obtaining the desired result. The experience of European Governments already mentioned shows that eradication by this method alone, when the disease has obtained a foothold, is practically impossible. For this reason, when the disease breaks out in a country like the United States, where the contagion is likely to spread rapidly by means of infected cars, manure, hay, and other feed, and where the results of its obtaining a firm foothold would be so disastrous, it seems that this method of temporizing is rather tedious, and more radical steps are required in order to suppress and eradicate completely the infection in the quickest and most thorough manner possible.
It would therefore appear better, after judicious appraisement, to concentrate the expense incident to the extermination of foot-and-mouth disease by purchasing and slaughtering all affected and exposed cattle. The carcasses of these animals should be totally destroyed, preferably by cremation, or otherwise by burying them in a hole 6 feet deep and covering them with air-slaked lime. The infected stable should be disinfected by thoroughly cleaning it, scrubbing the floor with hot water, brushing down all loose dust from the walls, and tearing off all woodwork which is partly decayed. Then the whole interior of the stable should be disinfected with one of the following substances:
All stable utensils should be thoroughly cleaned and disinfected by the application of a solution of one of the above-named disinfectants. The manure should be burned or disinfected and spread over ground (other than meadow land) that is to be turned under. No other cattle should be purchased for at least sixty days after the complete disinfection of the premises.
The success in eradicating the disease by combined quarantine, slaughter, and disinfection, as practiced in the United States, Denmark, Great Britain, and a few other countries, demonstrates in a striking manner the efficacy of slaughtering and the futility of relying upon quarantine alone to stamp out the disease.
Inoculation has been adopted in some countries in order to have the disease spread quickly through the herds, and while this practice has undoubted value where the disease is indigenous, it is not desirable in this country and should not be adopted.
As a rule medicinal treatment with a view of curing affected animals is not to be recommended under conditions prevailing in the United States, where the disease has not become established, and the first object is to stamp it out as quickly as possible. Even though most animals would recover, with or without treatment, it would be practically impossible, while they were being held for recovery, to prevent the spread of the infection to others. The disease would be liable to spread faster than it could be cured. As already pointed out, it has been found impossible to prevent absolutely the spread of the contagion by the strictest quarantine alone, under the usual farm conditions. In addition, the affected animals that have passed through the disease may become a source of further infection as virus carriers for weeks and months after they have apparently recovered, and are susceptible of reinfection, as one attack does not confer permanent immunity.
Foot-and-mouth disease in man.—Foot-and-mouth disease is primarily and principally a disease of cattle; secondarily and casually, a disease of man. It is transmissible to man through the eating or drinking of raw milk, buttermilk, butter, cheese, and whey from animals suffering from foot-and-mouth disease. It is also transmitted directly, though more rarely, from the salivary secretions or other infected material which may gain entrance through the mucous membrane of the mouth. It is doubtful whether the disease can be transmitted to man by cutaneous or subcutaneous inoculation, though it is probable that the infection may be communicated if the virus directly enters the blood through wounds of any kind. Children are not infrequently infected by drinking unboiled milk during the periods in which the disease is prevalent in the neighborhood, while persons in charge of diseased animals may become infected through contact with the diseased parts or by milking, slaughtering, or caring for the animals.
The symptoms in man resemble those observed in animals. There is fever, sometimes vomiting, painful swallowing, heat and dryness of the mouth, followed by an eruption of vesicles on the mucous membrane of the mouth, and very rarely by similar ones on the fingers. The vesicles appear on the lips, gums, cheek, and edge of the tongue, and are about the size of a pea. The vesicles soon rupture, leaving a small erosion which is soon covered by a thin crustunder which the new formation of epithelium proceeds rapidly. The skin eruption mostly appears on the hands, tips of the fingers, base of the nails, and more seldom on the toes and other parts of the body. Besides these local changes, during the course of the disease headache, pain in the limbs, vertigo, abdominal cramps, vomiting, diarrhea, and weakness are occasionally observed. The disease is seldom fatal, usually appearing in a very mild form except in weakened children, in whom an accompanying intestinal catarrh may lead to a fatal termination.
Veterinarians who have had considerable experience with the disease among animals regard the human affection as by no means uncommon in countries where foot-and-mouth disease prevails, but the disturbance of health is usually too slight to come to the notice of the family physician.
But few outbreaks of the disease in man have occurred in the United States, and therefore cases of its transmission to man in this country are rather rare. Dr. James Law reports having observed the disease in man from drinking infected milk during the epizootic of 1870 in the Eastern States, but the outbreaks of 1880 and 1884 affected such a small number of animals and were so quickly suppressed that no instance of its transmission to man was recorded. A few cases have been reported by Brush accompanying the New England outbreak of 1902. Similar reports have been likewise received concerning the appearance of vesicular eruptions in the mouths of children during the 1908 and 1914 outbreaks, and the history of these cases incriminates the milk supply.
Experiments by Loeffler and Froesch, as well as recent experiments which have been made in Denmark and Germany, indicate that the infection is comparatively easy to destroy by heat or the usual antiseptics. Milk pasteurized at a temperature of 60° C. for 20 minutes is safe so far as infection by foot-and-mouth disease is concerned.
These two names are applied to diseased conditions which are so nearly alike in their symptoms that it is sometimes difficult to distinguish the one from the other. Indeed, the name pyosepticemia, or septicopyemia, is often applied when it is impossible to make a distinction between septicemia and pyemia or where each is equally responsible for the diseased condition. The name septicemia is derived from two Greek words meaning "poison" and "blood," and signifies that the germ lives in the blood, hence the use of the term "blood poisoning" for this disease. Pyemia is likewise derived from two Greek words, meaning "pus" and "blood," and is that form of septicemia caused by pus-producing organisms and characterized by secondary abscesses.
Causes.—Neither of these diseases is brought about, strictly speaking, by any specific organism; hence neither can be looked upon as a specific disease. The organisms most frequently found in cases of septicemia are, on the whole, the same as those of pyemia, and may be pus cocci, the bacillus coli, or other pus-producing organisms. These organisms are often found as secondary invaders in other diseases, such as advanced cases of tuberculosis, in which cases they are responsible for the formation of pus.
Aside from the causative organism, or, in other words, the active cause, there are many secondary causes. The most important of these in pyemia is a break in continuity of the protective covering, as a wound, which affords an entrance into the tissues for the organisms. Among the different varieties of wounds may be mentioned cuts, bruises, punctures, burns, chemical or frozen wounds, and compound fractures of bones. Injuries received during parturition, stoppage of the milk ducts, and infection of the umbilicus in the newly born are also frequent causes of pyemia. Septicemia usually follows surgical wounds, local suppuration, enteritis, bronchitis—in fact, wherever there is a local lesion of any kind permitting germs to enter the blood. Septicemia was formerly applied to designate the condition in which the organisms were localized, but in which their toxins were diffused in the blood. Pyemia was made to represent that condition when the organisms were localized, but in which the pus was transported by the blood. These terms now are applied to conditions in which both the organisms and their toxins, or the pus, are present in the blood. The term septicemia is indicated when intoxication is the more pronounced symptom and pyemia if pus formation and metastatic or secondary abscess formation are observed.
Symptoms.—The symptoms of both diseases include primarily a high fever (104° to 107° F.). Coupled with this there is disinclination to move, the animal is depressed and not cognizant of its surroundings. The pulse is rapid, small, and feeble, respiration increased, mucous membrane injected, swollen, and of a yellowish tinge. Appetite is lost and death follows in the case of septicemia in from two to four days. In pyemia the symptoms come on more slowly and are not so intense as in septicemia, while the course of the disease is longer, lasting from six days to four weeks. The mortality is not so great as in septicemia, but the period of convalescence is always long.
Lesions.—Septicemia is characterized by the destructive changes in the blood, which is chocolate colored, noncoagulable, and swarms with bacteria. The lining membranes of the heart are studded with red spots, often running together to form a large hemorrhagic area. The lungs, liver, and kidneys may also show these hemorrhages. The spleen is enlarged and full of black blood. The cadaver decomposes very rapidly and in some cases forms great quantities of fetid gas. In pyemia, in addition to these lesions, abscesses are formed in the various organs throughout the body. If the disease develops slowly a post-mortem examination shows the abscesses to be the chief alterations. The pus content is usually greenish, stained with blood, and contains strings of fibrous tissue and necrosed matter.
Treatment.—Treatment is almost futile in advanced cases of either disease. Septicemia is usually fatal and pyemia frequently so. Prevention and the immediate treatment of local infections are the surest means of combating them. For local treatment of wounds the usual antiseptics are indicated, such as 3 per cent compound cresol or carbolic acid, or one one-thousandth bichlorid-of-mercury solution. For pyemia, where the abscesses are near the skin, they should be opened and treated antiseptically by injecting any of the previously mentioned germicides. General and heart stimulants are indicated, such as a drench containing digitalis 2 drams and alcohol 2 ounces. Quinin and calomel in repeated small doses of one-half dram each three times a day are sometimes beneficial. Camphor in the form of oil of camphor (camphor dissolved in 10 parts of sweet oil) is a good stimulant and has some antiseptic properties, which make it a valuable drug in combating these diseases when it is given in doses of 2 drams three times daily.
Hemorrhagic septicemia is a name applied to a highly fatal, infectious disease existing in various species of domestic and wild animals, from a microorganism having definite biological characters and possessing the properties of producing clearly defined and characteristic lesions.
This causal agent,Bacterium bovisepticum, belongs to the same group of cocco-bacilli as those causing chicken cholera, swine plague, and rabbit septicemia, and may be described as an ovoid, nonmotile, polar-staining bacterium with rounded ends, 1/38000 of an inch wide by 1/20000 of an inch long, sometimes seen in pairs and sometimes in chains.
Various names have been applied to this disease, and though the causative agent and the distinctive lesions are well known, it is more than likely that the affection is seldom recognized. It was described by Bollinger in 1878, and named Wild und Rinderseuche, from its having affected deer, wild boars, cattle, and horses in an epizootic which swept over Germany at that time. Before this, however, several epizootics of what was evidently the same disease had been well described, notably that which occurred in England in 1854. Since then it has occurred in epizootic and enzootic forms in many sectionsof Europe, Asia, Africa, and America. In this country the disease has been observed in Texas, Tennessee, New York, Minnesota, Pennsylvania, District of Columbia, South Dakota, and Wisconsin. Other names given to it are game and cattle disease, buffalo disease, barbone, pasteurellosis bovina, ghotwa, and infectious pneumoenteritis.
In earlier times it was evidently confounded with gloss anthrax, and even now it is probably mistaken in a great many instances for anthrax, blackleg, cornstalk disease, and cerebrospinal meningitis.
The disease is essentially a septicemia, or blood poisoning, and the microbic invasion occurs from inoculation probably either through abrasions of the skin or by injury to the mucous membranes from coarse fodder, etc. Moore and Smith have found in the mouths and nasal cavities of healthy animals, including cattle, bacteria belonging to this group; but these organisms proved to be nonpathogenic. As is well known, however, many pathogenic germs at times exist in a saprophytic state, and it is not hard to conceive how a microbe may cease such existence and assume parasitic or pathogenic properties when the surroundings are eminently favorable. This may be a connecting link in the etiology of sporadic outbreaks of the disease in which all other hypotheses as to its genesis seem untenable. The disease seems to occur most frequently in swampy or mucky localities or in pastures receiving the overflow from infected fields. It is said to occur usually in the spring of the year, when the melting snows and rains bring to the surface the subterranean waters from rich soils containing nitrogenous materials in which the bacteria have been existing. In a great many instances there does not seem to be any plausible explanation for an outbreak of the disease and one can only surmise as to its origin.
Symptoms.—Three forms of the disease are recognized, based upon the distribution of the lesions—the superficial, or cutaneous, the pectoral, or thoracic, and the intestinal form. The last is a usual accompaniment of the other two and may be mild or severe. Naturally the symptoms vary according to the violence of the attack and to the particular form of disease with which the animal is affected. In the superficial, or cutaneous, form the presence of a swollen tongue, throat, and dewlap, or even of the lower portion of the legs, gives us a clew to the trouble. An entire loss of appetite occurs, and in milk cows there is a diminution of the milk secretion. The temperature may be only slightly elevated, but it is usually very high. Salivation is set up by the inflammation of the mouth and pharynx. Unsuccessful efforts at eating and swallowing are made. There may be difficulty in breathing, depending on the amount of involvement of the larynx, trachea, bronchi, or lungs. There may be a blood-stained discharge from the nostrils, and the mucous membrane thereof will often show punctiform hemorrhages. The pulmonary form showsthe same symptoms as croupous pneumonia, with a frequent suffocative cough and oppressed breathing, or dyspnea. When the intestines are involved the patient strains to defecate, and passes shreds of intestinal mucus along with blood-stained feces. The urine also may be tinged with blood. Finally a severe diarrhea takes place, the animal becomes correspondingly weak, and death takes place in 24 to 36 hours. Cases may die in as short a period as six to eight hours, while in the pectoral form of the disease the animal may linger six or eight days. Cases have been reported which became chronic and in which death did not take place for a month or more. In some of the cases running an acute course, symptoms of toxemia are present; there is a lack of sensation of the skin, staggering gait, trembling, eyes fixed, neck at times bent to one side, and the eyes showing a wild expression. At times the animals appear as if in pain and look around at the flanks. In the pectoral form they may stand with the forelegs wide apart in evident effort to breathe more freely. Sometimes there is a champing of the jaws and a very free flow of glairy saliva dropping from the mouth.
The prognosis is decidedly unfavorable and 80 to 90 per cent of the cases result fatally.
Lesions.—The characteristic lesions of hemorrhagic septicemia consist of hemorrhagic areas in the subcutaneous, subserous, and muscular tissues, the lymph glands, and the viscera; in fact, they are distributed more or less widely throughout the body and vary in size from a mere speck to the diameter of a half dollar or even larger. The superficial form presents itself first as a doughy tumefaction of the skin about the region of the throat, neck, dewlap, or legs, which pits on pressure. This tumefaction consists essentially of a cerogelatinous exudate into the subcutaneous and intermuscular tissues.
Bloody extravasations may take place in subcutaneous tissues in various places, but they are usually seen about the lower portion of the neck. The mucous membranes and submucous tissues of the mouth, tongue, pharynx, and larynx become involved in the process and are greatly thickened, inflamed, and infiltrated with serum. The mucous membrane becomes reddish purple, and that of the nostrils may in addition show hemorrhagic spots on its surface. The lymphatic glands in this region are also swollen and infiltrated with bloody serum. The salivary glands are pale and dry. The pectoral type, though at times existing alone, may coexist with the cutaneous form. The inflammatory edema of the mouth extends to the mucous membrane of the trachea and bronchi, producing an extensive thickening and a yellowish infiltration. The lung shows interstitial thickening from the outpouring of serum into its meshes. It may become pneumonic.
The diaphragm, heart sac, and heart walls show numerous hemorrhagic points and larger bloody extravasations. Sometimes there is a serous pleurisy, with more or less fibrinous exudate. In the intestinal form the submucous and subperitoneal tissues show alterations from a few hemorrhagic spots to large bloody suffusions, or even gelatinous infiltrations. This latter is seen about the region of the pancreas and in the folds of the mesentery. There is a severe hemorrhagic inflammation of the intestines and a staining of the intestinal contents with blood. The muscular system throughout shows hemorrhagic areas. The abdominal viscera, liver, spleen, and kidneys often present hemorrhagic lesions.
Differential diagnosis.—Anthrax, which presents superficial swellings, like hemorrhagic septicemia, may be distinguished from that affection on post-mortem examination by the enlargement and engorgement of the spleen, the contents of which are soft and tarry. The blood of anthrax animals is very dark, and does not become light red on exposure to air, nor does it coagulate, while in hemorrhagic septicemia the blood is normal in appearance and coagulates. The detection of the anthrax bacillus in the blood would be final.
In blackleg the animals affected are usually under 2 years of age. The swellings are quite evident, and usually occur on the legs, above the knees or hocks, and are distended with gas, which crackles, or crepitates, when pressed upon. If one of these tumors is opened, a bloody serum will exude, and the gas gives off the odor of rancid butter. The internal hemorrhages are not general, although they may occur. A microscopic examination of the juices from the tumefaction will show the blackleg bacillus.
In cerebrospinal meningitis the causative agent is unknown, but probably exists in the feed. It may occur in any locality and at any season of the year. There are no local swellings, and cattle are not frequently affected.
Cornstalk disease may be differentiated from this affection from the fact that it always occurs after the cattle are turned into a cornstalk field, by its sudden onset, the absence of any characteristic symptoms or post-mortem lesions, and the failure to find the causative agent in the blood.
In making a post-mortem examination of animals affected with hemorrhagic septicemia, it would be well to examine the articular surfaces of the long bones, as it has been reported that they are frequently ulcerated. This should apply especially to those cases that have shown lameness.
Treatment.—Treatment is absolutely useless, so far as we know at present, and for all practical purposes prophylaxis alone should be relied upon. The same sanitary precautions, such as isolation, disinfection, and burial or burning of all dead carcasses, should beobserved as for anthrax and other highly infectious diseases. All the premises, barns, stalls, litter, and stable utensils should be thoroughly disinfected. Separate the apparently well animals from the sick by placing them in a separate lot.
Experiments by the Bureau of Animal Industry toward protective inoculation of the exposed cattle on infected premises have been made and the results have been so satisfactory that several commercial houses handling biological products are manufacturing a vaccine for hemorrhagic septicemia in accordance with the Government's experiments on this subject. The method of preparing the vaccine is similar to that recommended by Lignières. It consists in growing the cultures of the organism of the disease at 42 to 43° C. and preparing from them growing at this temperature two different strengths of vaccine. The weaker vaccine, which is used for the first injection, is grown for five days at this temperature, whereas the stronger vaccine, for the second injection, is grown for only two days. These vaccines are used with an interval of 10 days between the injections, the dose being 1 cubic centimeter at each injection. The effect of this vaccine in abating outbreaks already in progress has been highly satisfactory and it is plain that the general introduction of preventive vaccination for hemorrhagic septicemia must be of material benefit to the cattle raisers in the infected districts.
This contagious disease is called coital exanthema or vesicular exanthema, and is more or less prevalent on the Continent. It has also been observed in the breeding districts of the United States. It is the subject of legislation in Germany, and governmental statistics are published annually concerning its distribution in the Empire. According to the reports from Hungary 492 head of cattle were attacked during 1898, 587 in 1899, and 207 in 1900.
A similar or perhaps identical disease of horses has the same distribution and is transmissible from horses to cattle and vice versa.
The disease may be defined as a highly contagious eruption situated upon the external genital organs of both sexes and accompanied with little or no general disturbance of health. The contagion, the nature of which remains still unknown, is transmitted mainly during copulation. The bull may have the disease and convey it to all the cows with which he comes in contact, or he may become infected by one cow, and, although not showing the disease, he may, during copulation, transmit it for several days after to all other cows. Simple contact between one cow and another may convey the disease, or the sponges used in cleaning the diseased may carry the virus to the healthy. It has also been conveyed to healthy cows by these animals lying with their hind quarters against infected wooden troughs.
Symptoms.—The period between the infection and the appearance of symptoms is somewhat variable. It is usually given as three to six days. It may be briefer or much longer. In cows the mucous membrane of the vagina and the vulva become swollen, inflamed, very tender, and covered with dark-red spots. The secretion is very abundant and consists at first largely of serum and mucus resembling the white of an egg. Small vesicles then appear, which rapidly burst and are converted into excoriations or deeper ulcerations. The secretion becomes more purulent and is apt to dry in crusts about the root of the tail. The eruption is accompanied with much itching and difficulty in urinating. The walk may be stiff and awkward. In bulls the eruption is situated on the prepuce and the end of the penis, and consists of pimples, vesicles, and ulcers, as in cows. It is accompanied with a little purulent discharge from the prepuce, itching, and difficulty in urinating. In severe cases the inflammation and swelling may extend backward to the scrotum and forward upon the abdomen.
The disease lasts from one to four weeks and always terminates in recovery. The acute stage lasts only four or five days, while the complete healing of the inflammation is slow. The eruption is usually accompanied with very little general disturbance. If the pain and irritation are severe, there may be some light loss of appetite and diminished milk secretion in cows. The disease rarely causes abortion. Chronic catarrh of the vagina and permanent sterility frequently follow as sequelæ.
Treatmentneed not be resorted to excepting in severe cases. The secretion and exudation should be washed off and a mild antiseptic applied, such as a 1 per cent solution of carbolic acid (1 ounce to 3 quarts of water) or 2 per cent solution of cresol compound in water. Care must be taken not to carry the disease from the sick to the well by sponges, etc., which have come in contact with the affected organs. These should be destroyed. To prevent the spread of the disease the infected animals should be kept isolated until they have recovered.
Rabies is a disease preeminently affecting the canine race, although all warm-blooded animals, including man, are susceptible to the malady, which is always communicated through bites from a preceding case. It has required many years of patient, scientific research to lead the ablest investigators to a clear comprehension of the cause, nature, and characteristics of this affection. It was known and described several centuries prior to the beginning of the Christian era, and from the earliest dawn of history it has been feared and dreaded. Its terrible manifestations have always been surrounded with anatmosphere of awe and mystery, and it is not surprising that myths, fallacies, and misconceptions in regard to it have been common and widely accepted. As the investigations by which we have come to a tolerably clear understanding of the facts concerning rabies have been comparatively recent, and for the most part, have appeared in scientific periodicals, fallacies in regard to the disease continue to have a strong hold upon the public mind. For instance, it is still a widely prevalent belief that if persons or animals are bitten by a dog they are liable to become rabid if the dog should contract the disease at any future time. There is no foundation for this impression, and it would be a great comfort to many people who are now and then bitten by animals if the fallacy of this idea were known. All experience, both scientific and practical, goes to show that rabies is transmitted only by animals that are actually diseased at the time the bite is inflicted. Rabies is an infectious disease involving the nervous system and characterized by extreme excitability and other nervous disorders and always terminating in death. The contagion of this disease has never been isolated, but the fact that it is caused by a specific organism principally found in the nervous system is indisputable. For instance, if an emulsion of the brain of a rabid animal is filtered through a germ-proof filter, the filtrate will be harmless. This fact indicates that the infectious principle is not in solution, but is an organism withheld from the filtrate by the filter. This contagion can be propagated only in the body of an animal. It is transmitted naturally from one animal to another solely by bites, and the old idea of spontaneous appearance of the disease is absolutely fallacious. It may be produced artificially by inoculating susceptible animals with an emulsion of the brain or spinal cord, as well as the saliva, milk, and other secretions of the affected animal. The blood, on the contrary, seems to be free from the infectious principle. The saliva contains the virus, which, under natural conditions, is introduced into or under the skin on the tooth of the rabid animal. The disease is widespread, being found in many countries of Europe, Asia, and Africa, and in certain sections of the United States.
Owing to the rigid quarantine regulations enforced against dogs imported into Australia, that country remains absolutely free from the disease. Following the canine race, cattle seem to be the most frequently affected, probably because rabid dogs, next to their morbid desire to attack other members of their own race, have a better opportunity to bite grazing cattle than any other species of animal. The relative frequency of rabies in these two species of animals is indicated by the carefully compiled statistics of the German Empire, which shows that 904 dogs and 223 cows died of rabies in 1898, whilein 1899 there were 911 cases in dogs and 171 in cattle. The latter receive bites most frequently on the hind legs and in the hips and about the lower jaw. These places are most accessible to dogs, owing to the habit of cattle to drive their tormentors away by lowering their heads and using their horns. Every animal bitten does not necessarily develop the disease, but the per cent of fatalities has been variously estimated, and averages from 25 to 30. This, however, depends on the location and size of the wound as well as the amount of hemorrhage produced, and various other conditions. In general, the nearer the bite is located to the central nervous system and the deeper the wound inflicted, the greater the danger of a fatal result. In cases in which the hemorrhage resulting from the bite is profuse, there is a possibility that the virus will be washed out of the wound and thus obviate the danger of subsequent appearance of the disease.
The virus after being deposited in the wound remains latent for an extremely variable period of time, which also depends on the size and depth of the wound as well as its location and the amount of the virulent saliva introduced. Experiments have proved that the virus follows the course of the nerves to the spinal cord and along the latter to the brain before the symptoms appear. Gerlach, having collected the statistics from 133 cases, has found this time, known as the period of incubation, to vary from 14 to 285 days. The great majority of cases, however, contract the disease in one to three months after the bite has been inflicted.
Symptoms.—As in dogs, both furious and dumb rabies are met with, the former being more common in cattle. A sharp line of distinction, however, can not be drawn between these two forms of the disease, as the furious form usually merges into the dumb, from the paralysis which appears prior to death. The typical cases of dumb rabies are those in which the paralysis appears at the beginning of the attack and remains until death. The disease first manifests itself by a loss of appetite and rumination, stopping of the secretion of milk, great restlessness, anxiety, manifestation of fear, and change in the disposition of the animal. This preliminary stage is followed in a day or two by the stage of excitation, or madness, which is indicated by increasing restlessness, loud roaring at times with a peculiar change in the sound of the voice, violent butting with the horns and pawing the ground with the feet, with an insane tendency to attack other animals, although the desire to bite is not so marked in cattle as in the canine race. A constant symptom is the increased secretion of saliva with a consequent frothing at the mouth, or the secretion may hang from the lips in long strings. Constipation is marked, and there is manifested a continual, although unsuccessful, desire to defecate.Spasms of the muscles in different parts of the body are also seen at intervals. About the fourth day the animal usually becomes quieter and the walk is stiff, unsteady, and swaying, showing that the final paralysis is coming on. This is called the paralytic stage. The loss of flesh is extremely rapid, and even during the short course of the disease the animal becomes exceedingly emaciated. The temperature is never elevated, it usually remaining about normal or even subnormal. Finally, there is complete paralysis of the hind quarters, the animal being unable to rise, and but for irregular convulsive movements lies in a comatose condition and dies usually from the fourth to the sixth day after the appearance of the first symptom.
Anatomy.—If animals which have succumbed to rabies are examined post mortem, very slight evidence of disease will be found in any of the organs, and, indeed, the absence of any specific lesions may be considered as characteristic. The blood is dark and imperfectly coagulated. The throat is frequently reddened, and there may be small spots of extravasated blood in the intestines. The stomachs are usually empty. In the spleen there may be hemorrhagic enlargements (infarcts). The cadavers rapidly undergo decomposition.
Differential diagnosis.—It is not an easy matter to decide definitely that a given animal has rabies, since the symptoms given above belong in part to a variety of other diseases, among which may be mentioned the excitement seen in young animals following close confinement, certain vegetable and mineral poisons, acute enteritis, and alterations of the central nervous system in cattle, the most common of which is tuberculosis of the brain and its covering membranes. The post-mortem lesions, however, should assist in making a correct diagnosis. Tetanus may readily be differentiated from rabies by the persistence of muscular cramps, especially of the face and abdomen, which cause these muscles to become set and as hard as wood. In tetanus there is also an absence of a depraved appetite or of a willful propensity to hurt other animals or to damage the surroundings. The cow remains quiet and the general muscular contraction gives her a rigid appearance. There is an absence of paralysis which marks the advanced stage of rabies. The form of dumb rabies in dogs is characterized by the paralysis and pendency of the lower jaw, while in tetanus the jaws are locked. This locking of the jaws in cattle renders the animal incapable of bellowing, as in rabies. Finally, tetanus may be distinguished from rabies by the fact that the central nervous system does not contain the infectious principle, while in rabies the inoculation of test rabbits with the brain or cord of a rabid animal will produce the disease with characteristic symptoms after an interval of 15 to 20 days. This period of incubationis much longer than in tetanus, since the inoculation of rabbits with tetanus cultures invariably results in death after a short period and usually within three days. The positive evidence that a rabid dog has been near cattle would greatly assist in making a decision in doubtful cases.
The disease in dogs is pretty well recognized by most people, but in case a suspected dog is killed it is desirable to open the animal and examine the contents of the stomach. While feed is absent, a variety of odd things may be present which the abnormally changed appetite of the rabid dog has induced it to swallow. Among such things may be straws, sticks, glass, rags, earth, pieces of leather, and whatever the animal may have encountered small enough to be swallowed. This miscellaneous collection in the stomach of dogs, together with absence of feed, is regarded by authorities as a very valuable sign, and in case of doubt may be made use of by laymen. In important cases, however, the head of the dog, cow, or other suspected animal should be removed and sent to the nearest biological laboratory, where a positive diagnosis can be made within 36 hours by the histological examination of the plexiform nerve ganglia, and within two or three weeks by the intracerebral inoculation of rabbits with an emulsion of the brain of the suspected animal.
Treatment.—This is useless after the first appearance of symptoms. When, however, a wound inflicted by a rabid animal can be discovered, it should be immediately cauterized or even completely extirpated, care being taken to cut entirely around the wound in the healthy tissues. For cauterizing the wound, fuming nitric acid, the hot iron, and 10 per cent solution of zinc chlorid are the most efficacious. To afford an absolute protection, this should be done within a few moments after the bite has been inflicted, although even as late as a few hours it has been known to thwart the development of the disease.
Pasteur originated and perfected a system of preventive inoculation against this disease which has greatly reduced the mortality in human subjects. Its application to animals, however, is difficult and requires considerable time and expense. A method of vaccination applicable to animals, consisting of a single injection of a suspension of "fixed" rabies virus, is now being quite extensively employed by veterinarians. Sanitary regulations which seek to control effectively the disease by exterminating it among dogs are most likely to prove successful. The measures which are adopted to this end can not be discussed in this place, but it is a striking fact that where the muzzling of all dogs has been rigidly enforced, as in England and in certain German districts, the disease has been practically stamped out.
Tuberculosis is an infectious and communicable disease characterized in its early stages by the formation, in various organs of the body, of minute nodules or tubercles, which containMycobacterium tuberculosis, the cause of the disease.
The disease, in its various manifestations, has been known for many centuries, and legislative enactments having reference to the destruction of affected animals and forbidding the use of the flesh date far back into the Middle Ages. The opinions entertained regarding the nature and the cause of the malady varied much in different periods and very markedly influenced the laws and regulations in vogue. Thus, in the sixteenth century, the disease was considered identical with syphilis in man. In consequence of this belief very stringent laws were enacted, which made the destruction of tuberculous cattle compulsory. In the eighteenth century this erroneous conception of the nature of the disease was abandoned and all restrictions against the use of meat were removed. Since that time, however, its communicable nature has been established by many investigators, and the tide of opinion has again turned in favor of repressing the disease and prohibiting the sale of contaminated products.
Occurrence.—The statistics concerning tuberculosis show that it is a disease prevalent in all civilized countries. In some countries, such as the northern part of Norway and Sweden, on the steppes of eastern Europe and Russia, in Sicily and Iceland, and in Algiers, it is said to be quite rare.
The returns from testing British cattle with tuberculin, supplied by the Royal Veterinary College, as stated in March, 1900, showed that among 15,392 animals tested 4,105, or 26 per cent, reacted.
During the slaughter of cattle for pleuropneumonia careful examinations of the carcasses were made for tuberculosis. Of 300 head killed near Edinburgh 120, or 40 per cent, were tuberculous. Of 4,160 killed in England 20 per cent were tuberculous. Of one of these lots of cattle (451 animals) the president of the Lancashire Farmers' Association testified that they were fairly representative cattle—cows, heifers, and growing stock—a thoroughly mixed lot; 20 per cent of them had tuberculosis.
Of 398 bovine animals taken haphazard in the city of Manchester, 120, or 30 per cent, were tuberculous. Among them were 168 cows, 69, or 41 per cent, being tuberculous, and 2 having diseased udders.
The result of testing the Queen's herd at Windsor was that 36 out of 40, or 90 per cent, were found tuberculous.
The investigations made by the British Dairy Farmers' Association deserve particular attention, coming as they do directly from a cattle owners' organization. The council of this association "resolved to submit the general consideration of the question to a committee, with a view to some more definite understanding as to the possible extent to which tuberculosis exists in dairy cattle." The secretary was instructed to write to a number of dairy farmers being members of the association, asking their cooperation and the use of their herds for the application of the tests. Of the herds offered, 9 were selected, containing 461 cows and 12 bulls, and 188 of these animals reacted, being 40.8 per cent. There were among these cattle 335 Shorthorns, of which 119, or 35 per cent, reacted; 67 crossbreds, of which 28, or 42 per cent, reacted; 47 Ayrshires, of which 37, or 80 per cent, reacted.
Another experiment of much interest is that of the Cheshire County Council. The technical instruction committee set aside £250 to be used by a joint committee from the agricultural and horticultural schools and Worleson Dairy Institute for applying the tuberculin test to their herds. The tests were made February 15, 1899. The results were: Worleson herd of 54 animals, 16 diseased, or 29.6 per cent; agricultural school herd of 17 animals, 4 diseased, or 23.5 per cent. The Worleson herd consisted of Shorthorn cows. In each herd the purebred Shorthorn bull was tuberculous. The results of the tuberculin test were confirmed by the slaughter of the animals and examination of the carcasses.
Sir T. D. G. Carmichael, member of Parliament for Midlothian, gave evidence before the royal commission that his Polled Angus herd was tested in the spring of 1895. "The results of the test were fearfully unexpected and alarming." Of 30 tested 13 showed decided reaction—43 per cent. Again, he speaks of having 41 animals tested the same spring and 16 reacted—39.5 per cent.
Of 80 Shorthorn cattle intended for export which were tested 34 reacted, or 42 per cent.
Of a herd of 25 British Shorthorns recently tested in quarantine 40 per cent were found tuberculous.
The addition of these animals above referred to gives 20,930 head examined and 5,441, or 26 per cent, pronounced tuberculous. And these herds were not selected because they were supposed to be tuberculous, but represent the general cattle stock of the country. These animals included at least 470 head of Shorthorns, of which 170, or 34 per cent, were tuberculous.
To these facts may be added the evidence of Prof. Bang that in the first half of the nineteenth century tuberculosis was brought to Denmark by cattle from Switzerland, Schleswig, and England, and that the same thing is now going on in Sweden and Norway, particularly through English cattle. Also the evidence of M. Sivori,chief of section at the ministry of agriculture, Argentina, who has investigated tuberculosis in that country and who says that "30 or 40 years ago tuberculosis was unknown in Argentine cattle, and it is still unknown among the native (criollo) cattle. Its appearance dates from the introduction of pure breeding animals. Statistics prove that tuberculosis is observed among the grades— above all among those of the Durham and less among the Hereford."
Moreover, the reports of the royal commission of Victoria, Australia, and of the New Zealand department of agriculture show a large proportion of tuberculous cattle in those colonies, where the disease was almost certainly carried by British cattle.
In the same manner that tuberculosis has been carried from Great Britain to Denmark, Sweden, Norway, Argentina, and Australia, it has also been taken to Canada. In one herd of imported cattle slaughtered in the Canadian quarantine station, 13 of the 14 animals were found tuberculous. One of the largest Shorthorn herds in Canada was some time ago tested because an animal from it was condemned when offered for shipment to the United States. This herd was found to be very badly affected, and an effort is being made to eradicate the disease by the Bang method. A Canadian official publication says of another Shorthorn herd, which at one time had a very high reputation, that when an investigation in regard to tuberculosis was recently made the disease was found among ordinary cattle wherever animals from this herd had been introduced, and that this herd, which had been looked upon as one of the greatest benefits to the farming community, was really a danger, because it disseminated tuberculosis among the farmers' herds. Still another well-known herd recently attracted attention because four animals from it offered for export to the United States were all tuberculous.
From December 23, 1900, to February 19, 1901, the period that the department inspector tested all Canadian cattle intended for shipment to the United States, 140 purebred Shorthorns and 3 Shorthorn grades were tested, and of the total number 26, or 18 per cent, reacted. During the first month that this inspection was enforced, and when it may be assumed that the condition of the cattle most nearly represented what it had previously been, 74 cattle were offered for importation, and 18, or 24.3 per cent, were found tuberculous.
In justice to Shorthorn cattle it should be said in this connection that they are probably no more susceptible to tuberculosis than are other breeds, but the disease has been allowed to spread in certain herds and families to such an extent as to give a wrong impression concerning the breed as a whole.
The slaughterhouse statistics of Prussia show 14.6 per cent of the cattle and 2.14 per cent of the hogs to be tuberculous. In Saxony the percentage is 29.13 with cattle and 3.10 with hogs. In the city of Leipzig the figures are 36.4 for cattle and 2.17 for hogs. (Siedamgrotzky.) Of 20,850 animals in Belgium tested with tuberculin in 1896, 48.88 per cent reacted. (Stubbe.) Of 25,439 tested in Denmark from 1893 to 1895, 49.3 per cent reacted; and of 67,263 tested from 1896 to 1898, 32.8 per cent reacted. (Bang.)
Figures available in the United States allow us to make a reliable estimate of the extent of tuberculosis of cattle. The following summary is presented: