Chapter V: A. Moore and the present writer made a series of experiments at the

New York State Veterinary College. In the fœtal membranes and uterine mucus of a number of cows, aborting in different parts of the State and therefore long distances apart, we found a bacillus that in form and culture-experiments closely resembles bacillus coli commune. This was nearly always in pure cultures, and in the few cases showing other microbes, these were only such as inhabit the healthy vagina. Our bacillus was never found in the womb nor fœtal membranes of cows that had calved at the full period in healthy herds. It agreed in most respects with the bacillus found by Chester, but differed somewhat in fermentation tests. It differed also in proving fatal to rabbits when inoculated on these animals. Injected in the form of cultures into the vagina in three old pregnant cows it continued to live on the mucosa, producing more or less catarrh and muco-purulent discharge in the different cases, yet all three carried the calf to full time, one having calved on the 123d day after injection, the second on the 167th, and the third on the 190th.

The results obtained at the Delaware College Experiment Station and the New York State Veterinary College, do not differ so seriously, as either one does from those obtained in Europe, by Nocard, Bang, and the Scottish Abortion Committee. The facts that the same germs were found, either in pure cultures, or exceptionally, along with the normal microbes of the healthy vagina, in the womb, and fœtal membranes of every aborting cow, that they were never found in the healthy cow which had calved at full time, and that the generative passages were the seat of a catarrh, alike in the cows that aborted and in those that were inoculated with the abortion discharges, but did not themselves abort, are all but conclusive that this microbe is the essential cause of the abortion.

The single objection to this view, namely that the inoculated cows did not abort is explained by the fact that in the New York abortions it is the rule that the calf is carried six or seven months from the date of impregnation (the date of the presumptive infection) to that of abortion. It is to be further borne in mind that our experimental cows were old, and may have passed through the disease before and become in some measure immune, that they were dry during the experiment, and were subjected to no extraneous excitement that would predispose them to abort. The presumption is that had the experiments been started earlier in the gestation, the abortion would have come in due time. The microbe maintained its hold on the mucosa and continued to advance up to and beyond parturition.

Another distinction of the European abortions, is in the presence of the microbe in European form in the digestive organs of the calf, and that the viable calves of infected cows are liable to die of intestinal disorders a few days after birth. Galtier, the Marquis de Poncius and Pry insist strongly on this. On a farm on the estate of the Marquis, where abortion had prevailed for twenty years, the calves of infected cows show at birth, or very shortly after, symptoms of broncho-pneumonia and of a complication of nervous disorders. They are breathless, wheeze, discharge from the nose, cough, scour, have convulsions or other nervous trouble. A large proportion of such calves die; and their lungs are found in part red, consolidated and devoid of air and the bronchia contain a muco-purulent product. Lesions denoting inflammation of the serosæ of the lungs, liver and intestines are common. This coincidence of a fatal disease in many of the surviving calves is exceptional among the aborting herds of New York.

In noting the evidence of a wide difference between the prevalent American and European forms of abortion in cows, one should be prepared to go farther, and accept if need be, still other distinctive forms in each of the two continents. Any catarrhal condition of the uterine mucous membrane, is a recognized hindrance to conception, and cause of abortion, and we must recognize that the forms of invasion of the womb by pus microbes are as numerous as there are irritant germs capable of living in the membrane. The question as to how many of these can produce contagious abortion is to be determined by the susceptibility of the membrane to irritation by each germ, and whether the latter can retain all its power of survival and virulence in passing from one animal to another. The presumption is, therefore, in favor of a variety of forms of contagious abortion, each due to its own specific microbe or microbes, rather than of a single unvarying type of the disease. In some the affection appears to be a purely local one (American), the microbe being confined to the genital or genito-urinary mucosa, whereas in others the microbes (Bangs’, Galtier’s, etc.) live also in the blood producing a general infection.

Two great types at least have been demonstrated in Europe and America. Whether future investigation shall show the presence in one of these continents of the types as yet only known in the other, remains to be seen. If the particular forms should turn out to be limited to different continents we are at once confronted with the necessity of an international sanitary quarantine, and inspection. Matters are bad enough now in our dairying districts, but if we are to be open to the importation of new types of abortion, which do not mutually immunize against each other, but which may be taken one after another in succession through a series of years, they may easily become incomparably worse.

_Acquired Immunity._ The question of persistent abortion year after year, in the same animal, is most important. If a first contagious abortion entails a second, a third, a fourth and a fifth in the same animal, in as many successive years, then manifestly the preservation of such animal is a most wasteful economy, altogether independently of the danger of her transmitting the infection to healthy stock. If, however, she herself becomes immune after a first or second abortion, it may be profitable to retain her for milk production or breeding, provided that she can no longer infect susceptible cows with which she must come in contact.

_Acquired immunity_ of the individual cow is the rule after one or two abortions caused by the microbes with which we are at present most familiar. There are exceptions to this rule due to special nervousness and excitability of given cows, which tend to an indefinite repetition of the abortion, under the stimulation of pregnancy, of the continued presence of the microbe, or of some local disease (tubercle, tumor, parasite, etc.) of the ovary, womb or peritoneum. Yet statistics show that this only applies to a small proportion of cows and these the most nervous and excitable. The tendency toward insusceptibility to the deleterious action of the germ, which may still be present, is in the cow as a rule greater than the disposition toward a nervous encrease of the susceptibility. The difficulty of reaching a conclusion on this point depends on the fact that stockowners very commonly dispose of aborting cows, and as the freshly bought cows are usually attacked sooner or later, it is too confidently assumed that the old cows also would have continued to abort had they been retained. Many years ago, however, observant New York dairymen had noticed that the same cow rarely aborted over three years in succession, and in the great majority of cases not over two. The owner of a large herd, who has had much experience with the disease, assures me that the rule has been, that a cow did not abort with him a second time. The continuous abortion in a herd was mainly among newly purchased cows and others that had not been previously attacked, including heifers carrying first calf. The same is in a measure true of the European abortions.

Nocard says that after three to five years there is an acquired immunity. Only heifers and the cows that have been recently bought in, abort.

Penberthy, speaking of England, says that in case of repeated abortion in the same cow, the calf is carried longer each successive year until it comes to its full term.

Sand, in his symposium of the experience of Danish veterinarians, says it is quite exceptional that a cow should continue to abort, but outbreaks of abortion disappear spontaneously if no new cows are brought in.

Bang refers to a herd of 200 head of which 83 aborted in their first pregnancy, and of these only 20 aborted in the second, while 7 failed to breed. Counting the latter as having aborted, this amounts to less than one-third, while over two-thirds of the cows that aborted in the first gestation carried the calf to full time.

Paulsen quotes the case of a herd of 16, 7 of which aborted after service by a bull in an aborting herd. One of the seven was sold, but the remaining six all went full time in the following year.

Mörck records the case of a herd of 16 cows, the majority of which aborted in the same year. All the aborting cows were sold and fresh ones purchased. Next year the new stock aborted together with some of the cows that had been held over. He continued this course for eight years without any improvement, and then decided to keep the aborting cows as well as the others. In two years the affection disappeared from the herd.

Such small herds, in which all become early infected, and in which there is no further opportunity for the infection of susceptible animals (cows not yet infected, heifers in first gestation, new purchases), furnish a better opportunity than do large herds, to trace the acquirement of tolerance.

In a question of this kind, one must allow for variations in the different types of abortion caused by various microbes, but in the forms with which we are familiar in Europe and America, the acquired tolerance of the individual can be counted on with great confidence. It has indeed been largely traded upon by purveyors of antiabortion nostrums who promise to cure the individual cow, to which alone their drugs are administered. Two evils result: the stock owner’s money is paid for that which unaided, nature would have accomplished for him; and attention is withdrawn from the real necessity of the case, the prevention of the infection of freshly introduced animals. The nostrum vender thus secures for himself a growing market, as the yearly production of fresh cases in the same herds, appears to demand a constant use of the agent which appeared to work so well in the earlier ones.

_Immunized animal still infecting._ The cow that no longer aborts is not, therefore, a safe member of a herd. As an individual animal she has become resistant to the pathogenic influence of the germ, she is invulnerable to it to the extent that she no longer aborts, but her system and generative passages have acquired no such active bactericidal power over the microbe as to lead to its speedy destruction. The genital passages, once colonized, continue to be a field of growth of the bacillus long after its power to cause abortion in that particular animal has passed. Analogous cases can easily be quoted from the field of pathology. The horse that has apparently recovered from dourine still conveys the disease to others with which it has sexual congress; the recovered syphilitic person is by no means eligible for marriage; the recovered pig continues to carry the infecting swine plague bacillus in its air passages. In short, it is the rule that the immunized animal can with safety to itself carry a germ that readily infects its nonimmunized fellows.

In the case of infectious abortion this is one of the most dangerous elements, as the apparently healthy recovered cow receives no attention in the way of separation and disinfection, but is allowed to spread the infection through the bull that serves her in common with other cows and by being sold into new and healthy herds.

_Symptoms._ Contagious abortion sometimes takes the form of temporary sterility, the animal taking the male at frequent intervals, but failing to conceive. If conception takes place, the abortion is usually deferred until the fœtus has attained a considerable development—in cows till the third or seventh month; in mares till the fourth or ninth month; in ewes or sows till the tenth week.

Often times premonitory symptoms are entirely unobserved. Usually there may be detected some heat and enlargement of the mammæ, with a decrease in the milk yield, or a serous modification of the milk as in colostrum. Still more striking is a muco-purulent discharge from the vulva—opaque, white or yellow—in marked contrast with the perfectly clear, transparent mucus which appears in œstrum. The discharge may be densely white (in mares) or reddish, and may be accompanied by some swelling of the vulva and redness of its mucosa, which is dull, rough and granular, or even the seat of a papillary eruption. There is rarely hyperthermia or other constitutional disturbance, and in some cases the abortion is only discovered by the finding of the fœtus and its membranes in the gutter or pasture. The membranes are, however, not unfrequently retained, becoming offensively putrid. In other cases a muco-purulent discharge persists for a length of time, insuring sterility so long as it lasts, and causing ill health and emaciation. The fœtus is usually born dead.

The _lesions_ are confined to the generative organs. Bang, found an odorless, dirty yellow, flocculent, slimy and more or less watery exudate between the chorion and uterine mucosa involving the connective tissue between the chorion and arachnoid so as to render it thick and friable. These conditions were well marked in the French and English cases, and perhaps somewhat less so in the American, which are habitually slower in reaching the abortion. Bang found the uterine catarrh with the characteristic bacillus in cases in which the calf had been carried to full term, exemplifying the local presence and culture of the bacillus without the usual abortion outcome. The bacilli were occasionally, though not always, found in the body of the fœtus, and in some cases the dead and mummified fœtus was found in the womb, which had not been stimulated to its expulsion. He even found the bacillus in the mummified fœtus, and still virulent, after an apparent seclusion of seven months.

ABORTION IN MARES.

This follows the same general course as does the disease in cows. In certain American outbreaks (Kilborne and Th. Smith) it has been traced to a bacillus like the colon bacillus, propagated in the womb and genital passages, and which produced suppurating vaginal catarrh in cows and mares on which it was inoculated. It is liable to occur, without premonitory symptoms having been observed, and to be followed by no marked sequelæ, so that, as in most cases in the cow, it may be looked on as a purely local infection. In England, Penberthy, found it to occur not earlier than the fourth month of gestation, yet he adduces several cases in which the first case in a breeding stud occurred in four weeks after the introduction of an infected mare from an aborting stud. In America on large breeding farms the introduction of the infection has proved ruinous, as many as 70 or 80 per cent. of the mares having aborted in the same season.

The conclusion is inevitable, that as in the case of cattle, the sire may become the means of transmission, and that the same measures of prevention are demanded. The fact that the affection is less widely spread or injurious, than in cattle, is largely due to the usual presence of but one, two or three breeding mares on a farm, so that there is little opportunity for a rapid extension of the infection. Multiply and encrease our studs of breeding horses, as cows have been in our dairying districts, and abortion, once introduced, would prove equally infective, spreading and injurious.

_Therapeutics_ are useless in contagious abortion as the disease usually runs its course before any danger is suspected. If premonitory symptoms are observed, the abortion may sometimes be warded off for a time by secluding the animal in a quiet place and seeking to obviate labor pains by opiates and ounce doses of viburnum prunifolium.

_Prevention._ This is to be sought along two principal lines: 1st. The protection of a sound herd against the infection: and 2nd. The extinction of infection in a herd already diseased.

_Protection of a sound herd._ This requires the greatest possible care, because the infected animal usually presents the general appearance of perfect health, and there is no ready means of testing the presence or absence of the abortion bacillus. In purchasing a cow or mare in a public market the new owner may find her affected with this bacillus, and a serious danger to his whole herd. To protect the latter he must learn that the herd from which she came has had no abortions for several years before, and that the offspring for the different years are present in numbers corresponding to the dams. In the absence of this a certificate, and guarantee against infection of other animals by the one purchased, may well be demanded of the seller. A certificate from the veterinarian attending the herd furnishing the animal, may also be sought as evidence of the absence of abortion from the locality. Imported animals should be safeguarded in the same way but with even greater care, lest the microbian sources of new types of abortion, should be brought into the country. A guarantee of this kind might well be demanded by the Federal Government in the case of all breeding animals imported.

In case of failure to secure the most perfect guarantee with the purchased animal it would be worth the purchaser’s while to seclude it from his valuable herd, and not to breed it with the other animals of his herd until it has been proved to be entirely free from infection. If bought for a sire it should be subjected to a course of disinfection of the sheath and penis: if for a dam and unimpregnated, antiseptic irrigation of the vagina may be made daily for a week, and the external parts, hips and tail daily washed with antiseptics. If very important to have her bred, secure, if possible, a male that is not to be used on other animals. If this is impracticable, let the sheath and penis, and surrounding skin be thoroughly disinfected as soon as the service has been had.

If the newly acquired female is pregnant, keep her by herself until parturition and, even if this takes place at full term, irrigate the womb daily for a week with a disinfectant, delay having her served for a month, and if she must go to the sire of the herd, subject him to thorough disinfection after service. It may be that she still carries the germ but has become tolerant of it.

_Extinction of Contagious Abortion in a Herd._ 1. Two separate stables, or compartments, not having a common gutter should be provided, one for the sound animals, and one for those that are known to be affected, or that are open to suspicion.

2. The cow or mare that shows symptoms of abortion, or that has aborted, should at once be removed to the quarantine stable, and her stall, including the gutter and drain leading from it thoroughly disinfected. The whole stable should be whitewashed.

3. The aborted fœtus with its membranes, should be at once removed and burned, or boiled, or deeply buried after it has been thickly sprinkled with chloride of lime or other active disinfectant.

4. The manure from the infected stable should be taken into an enclosure into which no animals have access, and freely watered with a solution of sulphate of copper (6:100).

5. All in the quarantined stable and even those left in the general stable, should have the external generative organs, the hips, and the whole length of the tail washed once or twice a day with an antiseptic solution. Carbolic acid or creolin (2 or 3:100) makes a very safe and convenient agent, but copper sulphate (6:100) or mercuric chloride (2:1000) may be substituted. The colorless mercuric solution though effective and inodorous, has an element of danger in it, when left in barns in large quantities.

6. Cows or mares that have just aborted, should have the uterus irrigated daily for a week with a disinfectant solution. Carbolic acid (1:100 with 1 sodium carbonate) or creolin (1 to 2:100) or mercuric chloride (1:1000 with 1 hydrochloric acid) are good examples. Use a long rubber tube and funnel. They should not be bred until all discharge has ceased.

7. It is a good practice to keep a separate sire for the aborting and quarantined suspected animals, but the bull for each herd should, after each service, have his sheath injected with the disinfectant liquid, the orifice being held and the liquid pressed into all parts and finally, the skin around the sheath must be well washed with the same.

8. All cows or mares in an aborting herd, or one from which aborting animals have been removed within a year, should, after delivery, be injected with a disinfectant for one week exactly as if they had just aborted. This will guard against the danger from animals that carry the germ, but have become so tolerant of it that they no longer themselves abort.

9. New born animals brought in from other herds should be sponged all over with one of the above-named disinfectant solutions before being added to the herd.

10. In case the breeding animals go to pasture, separate fields should be furnished for the aborting and suspected ones and those supposed to be sound.

11. Breeding ewes, goats and sows should be excluded from all pastures occupied by suspected herds or those under treatment. The fields should further be cleared of rabbits as being susceptible to the infection and capable of keeping it up and transmitting it.

12. It is important to reserve the herd sires for the exclusive use of the home herds. Where this cannot be done, disinfection of the sheath and penis should be practised immediately after each service.

Attempts have been made at different times to destroy the bacillus by subcutaneous or intermuscular disinfectant injections. Bäuer used in the cow a 2 per cent. solution of carbolic acid, of which he injected two Pravaz syringefuls under the skin of the flank every fortnight from the fifth to the seventh month. It was rather unreasonable to expect much from 10 minims of carbolic acid once a fortnight, even apart from the fact that this agent is converted into the inert sulphophenic acid in the body.

Lignieres followed in the same line by injecting into the bodies of the cervical or other muscles 10cc. (2½ drams) of a mixture of terpinol one part, olive oil nine parts. This was injected during pregnancy every second day for the first three months, every third day for the second three months, and every fourth day for two months. The claim for success is based on the alleged prevention of second and third abortions in the same animals, and this becomes rather shadowy when we consider that the rule with cows is that they do not abort a second or third time. We have met with veterinarians who claimed a splendid success with the single injection of the terpinol. Lignieres claims no such success with his long continued treatment, as he had a percentage of abortions in every herd treated, and from first to last almost every animal in each herd aborted once, or was sold nymphomaniac. It is to be feared that the apparent immunity depended mainly on that tolerance which comes early in nearly every case to the aborting cow.

INFECTIOUS ENTERO-HEPATITIS IN TURKEYS.

Blackhead. Definition: Infectious protozoan disease of cæca and liver
and general toxicæmia. Microbiology: Amœba in cæca, liver, etc.
Symptoms: Attacks young, dulness, drooping, ruffling, moping,
anorexia, greenish diarrhœa, icteric or dusky mucosæ, blackening of
gobble, etc. Lesions: Enlarged thickened cæca, epithelial degeneration
and desquamation, exudation, mottled liver, with giant and round cells
and amœbæ, degeneration, necrosis, caseation, no abscess. Diagnosis
from bacteridian typhlitis or diphtheria. Treatment: Intestinal
antisepsis. Prevention: Disinfection of buildings, yards, manure,
seclude from other flocks, birds, flies, breed new flock on fresh
ground from eggs of affected or other flock, set in incubator or under
hens.

_Synonym_: Blackhead.

_Definition._ An infectious disease of turkeys, especially destructive to the young, due to a protozoön (amœba meleagridis), and characterized by inflammatory thickening of the walls of the cæca, diarrhœa, brownish, yellowish or greenish areas of degeneration of the liver, and congestion with blackish discoloration of those portions of the head which are uncovered by down or feathers.

_Microbiology._ The microörganism (amœba meleagridis) is found in the thickened walls of the cæca, in the exudate, in the lumen, and in the degenerating patches of the liver. The most common and simple form is that of a rounded body, varying slightly in form, and containing a group of very minute granules situated somewhat eccentrically. They may be enclosed in lymph spaces or less frequently in giant cells, or have portions of broken up cells adherent. Their size varies from 10 to 15μ. They may be stained by the following process: Harden in 95 per cent. alcohol saturated with mercuric chloride, then in the same with an equal amount of a 5 per cent. solution of bichromate of potash, and finally in Hemming’s solution. After a day in these solutions they are washed for a day in running water, then treated with ascending strengths of alcohol, dried by passing through alcohol and chloroform, imbedded in paraffin, sectioned dry, and stained in Delafield’s hæmatoxylin and eosin. The spherical or slightly oval amœbæ have a homogeneous, bluish red tint, feebler and therefore distinct from the tissue nuclei. Near the centre in most a blue circular line shows the outlines of the nucleus.

Th. Smith compares this affection with the amœbic dysentery affecting the large intestine and liver of man, and notes these differences, that amœbic movements have not been observed in amœba meleagridis, and that hepatic abscess does not occur in the turkey. The indisposition of the bird to suppuration may perhaps account for the latter distinction. Smith found rounded organisms in the tubules of the cæca and flagellates in the lumen of the gut, but did not attach any importance to their presence. Bacteria were only found in the lesions in the solid tissues where the subject had not been killed and immediately examined, but left over night for examination in the morning. There was no constancy in their species as in the case of the amœbæ, all indicating that their invasion was post mortem.

_Symptoms._ The disease is most frequent and fatal in the young (1 to 4 months, exceptionally 6 to 10 months), and the symptoms vary much in different cases, according to the intensity of the disease and the relatively extensive implication of the different organs. Among the general symptoms are those of general suffering and ill health, dulness, spiritlessness, drooping of the head between the wings, a pendent condition of wings and tail, erection of down or feathers, separation from the flock, the bird moping alone and sitting much of the time. The more characteristic phenomena which are rarely sufficient to identify the disease unless it is known to be prevalent, are loss of appetite, a greenish diarrhœa, yellowish or brownish discoloration of mucosæ, emaciation which becomes extreme if the subject survives long enough, and more or less blackish discoloration of the gobble and bare portions of the skin covering the head.

_Lesions._ These are characteristic, the cæca being greatly enlarged, the walls thickened by a yellowish submucous exudate, the epithelium disintegrated and desquamating, and the mucosa covered by a solid yellowish gelatinoid exudate arranged in superposed layers, while the contents are soft, pasty or of a greenish liquid appearance. The comparative stagnation of the contents as in the appendix of man appears to favor microbian infection. Amœbæ are especially abundant in the exudate into the submucosa and in the lymph spaces. The liver changes show infective inflammation in the spots of mottling, followed by degeneration, and necrosis, the liver cells disappearing under the compression of the giant and round cells and the amœbæ, the surface over the affected parts is depressed, and the mottling may show a variety of colors, as brown, brownish red, or yellow, pale yellow, grayish or dirty white. The degenerating tissue may become caseated, but abscess appears to be unknown, though so common in amœbic dysentery of man. In the skin of the head the blackish color predominates; there is more or less congestion, capillary embolism, and tissue degeneration.

_Diagnosis._ Th. Smith notes three cases of diseased cæcæ without great thickening of their walls, and an exudate in the lumen having the general appearance of that seen in the amœba disease but with no amœbæ, only the bacillus coli communis. The odor was strongly feculent. In all three cases the liver was healthy. In one there was an abundance of tapeworms in the bowels. Manifestly the absence of liver lesions may be held to indicate the absence of the protozoan disease. VonRatz (Budapest) gives two similar cases, with many nematodes, those in the exudate being 8 to 14 mm. long.

Zurn describes the presence of the diphtheria of fowls in the intestines of hens, turkeys and palmipeds and sometimes confined to the cæca. It is characterized by great prostration and debility, and an offensively smelling diarrhœa at first pultaceous and mucous, later bloody, and followed by constipation, in which case the cæca and rectum are ulcerated and blocked with the yellow croupous exudate. It lasts 2 to 3 weeks or even months, is subject to relapse, and sometimes occurs as a sequel to the diphtheritic affection of the head and throat. The absence of marked thickening of the cæcal wall, and of the protozoön, the presence of the diphtheritic exudate in the lumen, and the croupous condition or congested appearance of the head and throat are distinctive. Th. Smith, however, refers to two cases, supposed to be of this kind, in which the walls of the cæca were greatly thickened, the result of reparatory inflammation following a slough of the mucosa. Siedamgrotzky also describes thickening of the walls of both cæca in a hen, the mucosa being covered with a thin pseudo-membranous exudation, without ulceration.

It would seem that the cæca of birds, like the vermiform appendix of man is very subject to invasion microbes, bacterian and protozoan, and should always be carefully examined in case of intestinal or hepatic disorder.

_Treatment_ would be in the line of intestinal antisepsis with carbolic acid, salol, sulphurous acid, or the sulphites, with a laxative of castor oil, to carry these agents unchanged to the cæca, but no success has attended attempts in this direction, and the danger that comes from preservation of the infected animal, and consequent multiplication of the microbe would as a rule far more than counterbalance any probable recoveries.

_Prevention._ Moore has shown that the amœbæ, passed with the fæces, contaminate the food and water and thus actively propagate the disease, so that preventive measures must be mainly directed toward the purification of these infecting media. To be thorough new ground must be secured on which no diseased turkeys have been, and through which no water from contaminated or suspected land can flow; if necessary this must be closely fenced to prevent all ingress or egress, and on this ground we can place, as soon as they leave the shell, young turkeys hatched from eggs obtained in noninfected localities, or the eggs carefully washed of the turkeys living on infected ground. In this way the heredity and quality of the flock can be preserved without risk of contamination from the parents. The amœba is not known as a parasite of other birds, but if it should eventually be found to be so or to occupy any other animal body as an intermediate host, the local extermination of such host will become a necessary precaution.

When a new flock has been started in this way, the birds of the old flock may be fattened, killed and marketed, and as suggested by Cooper Curtice the grounds they have occupied may be secluded by fencing for one or two years, in the hope that the amœba will perish by this break in the chain of its life history. If this should prove successful with the land, the infection might be easily exterminated in the whole infected district or state.

The poultry buildings will require thorough disinfection. All manure and droppings must be carefully removed and the building whitewashed, using freshly burned quicklime and ¼ lb. of chloride of lime to the gallon of the mixture. The litter should be burned, and all nests, roosts, drinking vessels and troughs soaked with a mixture of sulphuric acid ½ gallon, carbolic acid ½ gallon, and water 20 gallons, (Th. Smith). The agents are mixed slowly in a vessel set in cold water. The same may be liberally applied on the surface, fences, etc., of the yards. Or quicklime, freshly burned, may be used freely on the yards holding the infected flocks (Moore). Mercuric chloride is dangerous. When the infected flock has been finally disposed of, the buildings and yards should be again thoroughly disinfected, and together with the field runs, abandoned for at least one year.

ASTHENIA IN CHICKENS.

Microbiology: bacillus of colon group. Pathogenesis to Guinea pigs:
rabbits, pigeons and chickens refractory to artificial cultures.
Treatment.

_Synonym._ “Going Light,” Bacterial Infection of the Duodenum.