SPECIAL REPORT ON DISEASES OF CATTLE TEXT

at first alternates with constipation, but finally becomes continuous. The disease lasts from two to five months, when the most extreme cases succumb. Most of the German cattle are said to be infested with liver flukes, but even when a large number are present the nourishment of the cattle is not disturbed. Thickening of the gall ducts, so that a so-called "Medusa's head" forms on the surface of the liver toward the stomach, appears in even well-nourished animals; even in cases of a cirrhosis of the liver it is seldom that any effect upon the cattle's health can be noticed, and so long as a portion of the liver tissue about twice the size of the fist remains intact, the nourishment of the animal may be comparatively good. It is rare that one sees a generalized edema in slaughtered cattle as a result of fluke invasion, and even in the heaviest infections of young cattle only emaciation is noticed. _Treatment._--Medicinal treatment is unsatisfactory. The disease may be prevented to a considerable extent by giving animals plenty of salt, and by introducing carp, frogs, and toads into infected districts; these animals destroy the young stages of the parasite and feed upon the snails which serve as intermediate hosts. The drainage of wet pastures and the avoidance of swampy lands for grazing purposes are important measures in the prevention of fluke diseases. Railliet and others have recently recommended the application of lime to fluky pastures, having discovered that very weak solutions are destructive not only to fluke embryos but to snails. This application is to be made during the summer months at the rate of about 500 to 1,000 pounds of lime per acre. The same authors also recommend extract of male fern for the treatment of fluke disease. Moussu states that the average dose for cattle is 1 gram of the extract for each 10 kilograms of live weight; that is, 10 grams for a young animal weighing 100 kilograms (about 220 pounds) up to 50 grams as a maximum for large animals weighing 500 kilograms (about 1,100 pounds) or more. The extract is mixed with about 5 times as much non-purgative oil and the dose is administered each morning for five consecutive days two hours before the animal is allowed to feed after having been fasted over night. The extract of male fern used should have a guaranteed strength of 22 to 25 per cent of filicine and 3.5 per cent of filicic acid. [Illustration: FIG. 19.--The common liver fluke (_Fasciola hepatica_).] [Illustration: FIG. 20.--The large American fluke (_Fasciola magna_).] [Illustration: FIG. 21.--Portion of grass stalk bearing three encysted cercariÊ of the common liver fluke (_Fasciola hepatica_). Enlarged.] TAPEWORM CYSTS OF LIVER AND OTHER VISCERA. Three kinds of tapeworm cysts are found in the viscera of cattle. One of these (_Multiceps multiceps_, or _C[oe]nurus cerebralis_) will be further referred to in the discussion of gid (p. 528). All these are the intermediate stages of tapeworms, which live when mature in the intestines of dogs, wolves, and other canines. The eggs of the tapeworms are scattered over the fields in the droppings of infested dogs or wolves, and when swallowed in food or water by cattle hatch out and the embryos migrate to the liver, mesentery, lungs, brain, or other organs, where they develop into cysts, variously known as hydatids, bladder worms, water balls, etc. When organs of cattle thus infested are eaten by dogs or wolves the cystic worms are also liable to be swallowed and then develop into mature tapeworms. To prevent cattle from infection with these parasites stray dogs, wolves, and coyotes should be killed wherever found, and dogs too valuable to kill should be kept free from tapeworms. As a precaution against infection with tapeworms, the viscera of cattle, sheep, or hogs should not be fed to dogs unless cooked. HYDATIDS (_Echinococcus granulosus_) form tumors (fig. 22) of varying size (sometimes as large as 6 inches in diameter) in the liver, lungs, and other organs. Their contents are liquid, resembling water. The presence of these parasites can not be detected in the living animal and there is no medicinal treatment for them. Organs containing hydatids should be destroyed by burning in order to prevent their being eaten by dogs. This is especially important, as dogs infested with the tapeworm stage of this parasite are a menace to human beings on account of the danger of infecting them with hydatids, which develop in man if the eggs of the hydatid tapeworm are swallowed. THIN-NECKED BLADDER WORMS (_TÊnia hydatigena_, fig. 23) are most commonly found attached to the mesentery and omentum. There is no medicinal treatment. GID.--Bladder worms (_Multiceps multiceps_, or _C[oe]nurus cerebralis_), which are occasionally found in the brain of cattle and cause gid, "turnsick," or "staggers," deserve mention, as they are rather common among sheep in the Northwest. As already alluded to, these worms are the intermediate stage of a tapeworm found in dogs, and their life history and the means of preventing infection have been briefly discussed above (see p. 527). Cattle harboring this parasite show symptoms indicating an affection of the brain, walking or turning in circles, dizziness, uneven gait, impaired vision, etc. Treatment consists in trephining the skull and removing the parasite, an operation which requires a skillful operator and is frequently unsuccessful. Unless the parasite is removed affected cattle almost invariably die. [Illustration: FIG. 22.--Hydatids (_Echinococcus granulosus_) in portion of hog's liver.] [Illustration: FIG. 23.--Thin-necked bladder worm (TÊnia hydatigena) from abdominal cavity of a steer.] TAPEWORM CYSTS IN THE MUSCLES, BEEF MEASLES.[19] Small tapeworm cysts (_TÊnia saginatÊ_), about the size of a pea, found in the muscles of cattle are the larvÊ of the common tapeworm of man. Cattle become infected from feed or water which has been contaminated by the feces of persons harboring the adult tapeworms, and human beings in turn become infected by eating raw or rare beef infested with the larval stage (measly beef). To prevent cattle from becoming infested with this parasite care should be taken that human feces are not placed where they will contaminate the feed or drinking water. This parasite is very common in cattle in the United States, at least 1 per cent being infested. As a result considerable loss is entailed through condemnations of beef carcasses by meat inspectors, because of the presence of tapeworm cysts. All this loss could be avoided and the danger of tapeworm infestation in human beings from this source could be removed by the observance of proper precautions in disposing of human excreta. At the same time much sickness and many deaths from diseases (hookworm, typhoid fever, etc.) caused by soil pollution would be prevented, and farm life would be rendered much safer than under the poor sanitary conditions which are responsible for the high percentage of tapeworm cysts among cattle in the United States. THREAD WORMS IN THE ABDOMINAL CAVITY. Thread worms (_Setaria labiato-papillosa_) 2 to 4 inches long are frequently found in the abdominal cavity. They seem to cause little or no trouble. The embryos produced by these worms enter the blood vessels. According to NoÈ, they are spread from one animal to another by stable flies (see p. 503), but this has not been definitely proved. The roundworms found occasionally in the anterior chamber of the eye (see p. 531) are perhaps immature forms of this species which have reached this location during their migration. LUNG WORMS. Lung worms (_Dictyocaulus viviparus_, fig. 24) in cattle are thread-like worms 2 to 4 inches long, found in the bronchial tubes and producing a condition known as verminous bronchitis. The life history of the parasite is not fully known, but infection is evidently derived through the medium of pastures where infested cattle have grazed. In the later stages of the disease the cattle cough, especially at night. Young cattle are more seriously affected than old animals. _Treatment for lung worms._--Various treatments have been advocated for lung worms, including fumigating with different substances and injections of remedies into the trachea by means of a large hypodermic syringe or by a special spraying apparatus, but none have been very successful from a practical standpoint. About all that can be done is to feed affected animals well and protect them from exposure, removing them from the pasture and keeping them in dry yards or stables maintained in a cleanly, sanitary condition. The methods of prevention in general are similar to those described under the discussion of the twisted stomach worm (p. 521). [Illustration: FIG. 24.--Lung worm (_Dictyocaulus viviparus_) of cattle. Outlines showing natural size of male (above) and female.] PARASITES OF THE BLOOD. Certain flukes (_Schistosoma bovis_ and related species) which live in the blood vessels (the large veins) of cattle in tropical and sub-tropical countries cause bloody urine and diarrhea, the feces being mixed with blood. These parasites have not yet been discovered in the United States, although the natural conditions are such in some parts of the country that they are liable to become established if introduced. The embryos of _Setaria labiato-papillosa_ (p. 529) which occur in the blood may be found by microscopical examination. They apparently cause no trouble. The organism which causes Texas fever is a protozoan parasite (_Piroplasma bigeminum_) of microscopic size, which lives in the blood and attacks the red blood corpuscles. For a discussion of this parasite and the disease which it produces see page 476 of this volume. Other parasites which live in the blood cause serious diseases known as surra and nagana (p. 500), but as yet neither of these diseases has gained a foothold in the United States. PARASITES OF THE EYE. Small roundworms, one-third to four-fifths of an inch in length, may occur in the ducts of the lacrimal glands. Several species all belonging to the same genus (_Thelazia_) are known. They sometimes escape from their usual location and may be found on the surface of the eyeball beneath the lids, or even in the eyeball. It has been supposed by some writers that the worms seen in the interior of the eyeball ("snakes in the eye") are immature stages of _Setaria labiato-papilosa_ (see p. 529) which have gone astray from the normal course of their migration, but the correctness of this supposition is uncertain. Worms in the eyes and lacrimal ducts may cause inflammation, in which case the eyes may be syringed with an antiseptic, such as a weak solution of coal-tar stock dip, and iodoform ointment applied if the condition is severe. When worms are present in the eyeball itself, their removal depends upon surgical treatment, usually not advisable, as the worms in that location either cause but little trouble or disappear without treatment. FOOTNOTES: [11] Further information may be found in a very full report on "Insects Affecting Domestic Animals," issued as Bulletin 5, new series, of the Bureau of Entomology of this department. [12] Further information on fly repellents may be found in Bulletin 131 of the Department of Agriculture. [13] For further information consult Farmers' Bulletin 1097. [14] For further information consult Circular 115 of the Bureau of Entomology. [15] For further information consult Farmers' Bulletin 857. [16] For further information see Farmers' Bulletin 909. [17] For a fuller discussion see Farmers' Bulletin 1017, issued by the U.S. Department of Agriculture. [18] For a more complete discussion consult Farmers' Bulletin 1057, Bulletins 130 and 152 of the Bureau of Animal Industry, and Bulletins 15 (technical series), 72, and 106 of the Bureau of Entomology, all issued by the United States Department of Agriculture. [19] For further information consult Bureau of Animal Industry Circular 214. MYCOTIC STOMATITIS OF CATTLE. By JOHN R. MOHLER, V. M. D., _Chief, Bureau of Animal Industry._ INTRODUCTION. Numerous letters have been received by this bureau in recent years relative to the existence of a disease affecting the mouths and feet of cattle in certain Eastern and Central Western States. Later reports indicate that the malady has made its appearance in the Southwest, where it has caused much alarm among the stockmen owing to its similarity to the foot-and-mouth disease of Europe. The disease, which is to be discussed under the name of mycotic stomatitis, has been carefully investigated by this department on various occasions, and it is with the view of giving the results of these clinical investigations as well as to assert its noninfectiousness and to differentiate it from the virulent foot-and-mouth disease, which it so closely simulates, that this article is prepared. NAME AND SYNONYMS. The name stomatitis signifies that there is present in the affected animals an inflammation of the mucous membrane of the mouth. This inflammation, which quickly develops into ulcers, is one of the principal and most frequently observed lesions. Mycotic stomatitis refers to that form of stomatitis which results from eating food containing irritant fungi. Thus the name not only suggests the cause of the disease, but also indicates the location of the earliest and most prominent symptoms. Other names which have been applied to this disease by different writers are sporadic aphthÊ; aphthous stomatitis; sore mouth of cattle; sore tongue; benign, simple, or noninfectious foot-and-mouth disease; mycotic aphthous stomatitis; and sporadic stomatitis aphthosa. CHARACTER OF THE DISEASE. Mycotic stomatitis is a sporadic, or noninfectious, disease which affects cattle of all ages that are on pasture, but more especially milch cows. It is characterized by inflammation and ulceration of the mucous membrane of the mouth, producing salivation and inappetence, and secondarily affecting the feet, which become sore and swollen. Superficial erosions of the skin, particularly of the muzzle and of the teats and udders of cows, may also be present, with some elevation of temperature and emaciation. CAUSE. This disease, as its name indicates, results from the eating of forage containing fungi or molds. It is probable that more than one fungus is involved in the production of this disease, but no particular species has been definitely proved to be the causative factor. Several attempts have been made by the writer to determine the exact cause and also to transmit the disease to other animals by direct inoculation, but with negative results. Suspicion, however, has been directed by various observers to the Uromyces and the red and black rusts that occur on clovers. These fungi cause very severe irritation of the lining membrane of the mouth, producing sometimes a catarrhal, at other times an aphthous, and occasionally an ulcerous stomatitis. The fungus of rape, etc. (_Polydesmus excitiosus_), is very irritating to the mouths and feet of cattle, causing severe inflammation and in some instances producing symptoms that have been mistaken for foot-and-mouth disease. The fungi (Penicillium and Puccinia) found on grasses have also been credited with the production of stomatitis. The fact that this disease disappears from a locality at a certain time and reappears at irregular intervals would suggest the probability that certain climatic conditions were essential for the propagation of the causative fungi, since it is well known that the malady becomes prevalent after a hot, dry period has been followed by rain, thus furnishing the requirements necessary for the luxuriant development of molds and fungi. Owing to this fact the disease is observed in one locality during one season and in an entirely different section another year, but reappears in the former center when favorable conditions prevail. In this way the affection has occurred at irregular intervals in certain sections of both the United States and Canada. SYMPTOMS AND LESIONS. Among the first symptoms observed in mycotic stomatitis are inability to eat, suspension of rumination, frequent movements of the lips with the formation of froth on their margins, and in some cases a dribbling of saliva from the mouth. There is a desire to eat, and frequent attempts to take food are made, but prehension is very difficult. If, however, feed is placed on the back of the tongue, it is readily masticated and swallowed. If the mouth is examined at this time, it will be found red and hot, and exceptionally small blisters will be seen, which, however, quickly become eroded and develop into active ulcers varying in size from one-eighth to 1 inch in diameter. Where several ulcers have coalesced a large and irregularly indented patch is formed. These erosions are most frequently found on the gums around the incisor teeth, on the dental pad, inside the lips, and on the tip of the tongue, but they also occur on the cheeks, interdental space, and dorsum of the tongue. The ulcers have a hemorrhagic border, a depressed suppurating surface, and contain a brownish or yellowish colored dÈbris, which is soon replaced by granulation tissue. As a result of this sloughing of the tissues and the retention of food in the mouth, a very offensive odor is exhaled. The muzzle becomes dry and parched in appearance, which condition is shortly followed by erosions and exfoliations of the superficial layer of the skin. Adherent brownish crusts and scabs form over the parts, and similar lesions are seen around the nostrils and external surface of the lips. In some cases there are associated with these alterations a slight swelling and painfulness in the region of the pasterns, at times affecting the forefeet, at other times the hind feet, and occasionally all four feet. In a few cases the swelling may extend above the fetlock, but it has never been observed above the knee or hock. The skin around the coronet may occasionally become fissured and the thin skin in the cleft of the foot eroded and suppurated, but without the formation of vesicles. As a result of these feet lesions, the affected animal may assume a position with its back arched and the limbs propped under the body as in a case of founder, and will manifest much pain and lameness in walking. If it lies down, the animal shows reluctance in getting up, and although manifesting no inclination to move about, when forced to do so there is more or less stiffness and a tendency to kick or shake the foot as if to dislodge a foreign body from between the claws. In some outbreaks the milch cows have slight superficial erosions on the teats which at times extend to the udder. The cracks in the skin are filled with serum and form brownish-colored scabs. The teats become tender and the milk secretion diminishes; in some cases it disappears. A similar tendency toward the formation of fissures and scabs on the skin of the neck and shoulders has manifested itself in a recent outbreak in Texas, and this feature was likewise noticeable in the disease when it occurred in Maryland and Virginia in 1889. In mild cases only the mouth lesions may be observed, or these alterations may be associated with one or more of the other above-described symptoms, but in severe cases, where there is a generalized mycotic intoxication, one animal may show all these alterations. When the disease is well developed the general appearance of the animal is one of great lassitude, and it either stands off by itself with hind feet drawn under the body and its forefeet extended, or it assumes a recumbent position. Owing to the inability to eat and to the general systemic disturbance present, the animal loses flesh very rapidly and becomes greatly emaciated in the latter