Special Report on Diseases of Cattle Part 70

THIN-NECKED BLADDER WORMS (_Taenia 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.

[Ill.u.s.tration: FIG. 22.--Hydatids (_Echinococcus granulosus_) in portion of hog's liver.]

[Ill.u.s.tration: FIG. 23.--Thin-necked bladder worm (Taenia hydatigena) from abdominal cavity of a steer.]

TAPEWORM CYSTS IN THE MUSCLES, BEEF MEASLES.[19]

Small tapeworm cysts (_Taenia saginatae_), about the size of a pea, found in the muscles of cattle are the larvae 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 carca.s.ses 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 l.a.b.i.ato-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 Noe, 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).

[Ill.u.s.tration: 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 b.l.o.o.d.y 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 l.a.b.i.ato-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 l.a.b.i.ato-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 STOMAt.i.tIS 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 stomat.i.tis, 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 a.s.sert 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.