The position on all fours is preferred by some authorities, who believe that more of the remedy is likely to reach the fourth stomach when the animal is dosed standing than when dosed in other positions.
Great care should be used in dosing to prevent the entrance of the liquid into the lungs, and in the preparation and administration of the remedy to avoid getting the solution too strong or the dose too large.
Bluestone, or copper sulphate, has been extensively used in South Africa in the treatment of sheep and cattle for stomach worms and is recommended by the colonial veterinary surgeon of the Cape Colony as the best and safest remedy. To prepare the solution take 1 pound (avoirdupois) of pure bluestone, powder it fine, and dissolve in 9-1/2 gallons of warm water. It is better first to dissolve the bluestone in 2 or 3 quarts of boiling water, then add the remaining quant.i.ty of cold water, and mix thoroughly.
This solution may be given to cattle in the following-sized doses:
Calves 3-1/2 to 4 fluid ounces.
Yearlings 6 fluid ounces.
Two-year-olds and over 12 to 16 fluid ounces.
In making up the solution only clear blue crystals of bluestone should be used. Bluestone with white patches or crusts should be rejected. It is especially important that the bluestone and water be accurately weighed and measured, and that the size of the dose be graduated according to the age of the animal.
The special value of medicated salts advertised under various trade names as preventives against worms is problematical. Commonly they contain little else than ordinary salt, the other substances being in such small quant.i.ty that their therapeutic effect is practically negligible. Definite evidence that they are more efficacious than plain salt is not yet available and their use is not recommended.
[Ill.u.s.tration: FIG. 13.--Twisted stomach worms (_Haemonchus contortus_).
Outlines showing natural size of male (above) and female.]
[Ill.u.s.tration: FIG. 14.--Twisted stomach worms (_Haemonchus contortus_).
Male (_a_), female (_b_), and egg (_c_). Enlarged.]
[Ill.u.s.tration: FIG. 15.--Larva of twisted stomach worm (_Haemonchus contortus_) coiled on tip of gra.s.s blade. Enlarged.]
[Ill.u.s.tration: FIG. 16.--A drenching tube made from an ordinary tin funnel, a piece of rubber hose, and a piece of bra.s.s pipe.]
THE ENCYSTED STOMACH WORM (OSTERTAGIA OSTERTAGI).
This parasite is as thick as a fine hair and less than half an inch in length. It lives in small cysts in the wall of the fourth stomach (fig. 17) and is also found free in the cavity of the stomach. When numerous, these parasites cause a thickening of the stomach wall and disturb its digestive functions. The symptoms caused by this parasite are very similar to those produced by the twisted stomach worm. The life history of the encysted stomach worm is not known in detail, but it is undoubtedly very much the same as that of the twisted stomach worm. The same measures as recommended above for preventing infection with the twisted stomach worm should be used. Medicinal treatment would seem to be of little use, owing to the protected position in which the parasite occurs.
[Ill.u.s.tration: FIG. 17.--Piece of lining of fourth stomach, showing cysts of the encysted stomach worm (_Ostertagia ostertagi_).]
INTESTINAL PARASITES.
TAPEWORMS.
Two species of tapeworms (fig. 18) are known to occur in the small intestine of American cattle. They sometimes grow to a length of several yards and to a breadth of three-fourths of an inch. Small portions of tapeworms, consisting of one or more segments, are occasionally seen in the droppings of infested cattle. The life history is not known, but the infectious stage is undoubtedly taken in with the feed or water, infection being spread by the eggs of the parasite contained in the feces of infested animals. The eggs are perhaps swallowed by some small creature (an insect, worm, or snail) which acts as an intermediate host, and which when accidentally swallowed by a cow while grazing or drinking carries with it into her stomach the infectious stage of the tapeworm.
Adult cattle do not seem to suffer much from infestation with tapeworms, but in calves these parasites may cause scouring and emaciation.
_Treatment._--Medicinal treatment for tapeworms in cattle is usually unsatisfactory, but the bluestone treatment used for stomach worms and mentioned above (p. 522) sometimes expels tapeworms. a.r.s.enic in doses of 1-1/2 to 3 grains has been claimed to give good results in the treatment of calves for tapeworms. From results obtained at the Oklahoma Experiment Station in the treatment of tapeworms of sheep it would appear that the efficacy of the bluestone treatment against these parasites may be increased by the addition of tobacco. For use on cattle the bluestone and tobacco mixture may be prepared as follows: 13 ounces of snuff or powdered tobacco is soaked over night in about 8 gallons of water. To this decoction is added 1 pound of copper sulphate which has been dissolved in 2 or 3 quarts of boiling water. Sufficient water is then added to the mixture to make a total of 9-1/2 gallons. The doses of this solution are the same as for the simple copper sulphate solution, described on page 522, namely:
Calves 3-1/2 to 4 fluid ounces.
Yearlings 6 fluid ounces.
Two-year-olds and over 12 to 16 fluid ounces.
[Ill.u.s.tration: FIG. 18.--A tapeworm (_Moniezia planissima_) which infests cattle.]
ROUNDWORMS.
A large roundworm (_Ascaris vitulorum_) measuring 6 to 12 inches in length, sometimes found in the intestines of cattle, especially calves, may cause inflammation and occasionally rupture of the intestine. Infection occurs through the swallowing of the eggs of the parasite in feed or water which has been contaminated with the feces of infested cattle.
A number of species of small roundworms, varying in size from an eighth of an inch to an inch or more in length, occur in the intestines. Of these may be mentioned the hookworm (_Bunostomum phlebotomum_) and the nodular worm (_[OE]sophagostomum radiatum_). The former is about an inch long and is found in the small intestine. The latter is somewhat smaller and is found in the cec.u.m and large intestine. Hookworms, when numerous, may cause anemia and other symptoms similar to those caused by stomach worms (see p. 519). The injury to the mucous lining of the intestine from the bites of hookworms may cause severe inflammation, and affords an avenue of infection with the germs of various diseases. The adult nodular worms apparently do not attack the wall of the intestine, but derive their nourishment from the intestinal contents. Several species of small, very slender roundworms (_Trichostrongylus_), less than a quarter of an inch in length, sometimes occur in the small intestine and fourth stomach, and a severe gastroenteritis, or inflammation of the stomach and intestines, has been attributed to them. One species of small roundworm (_Cooperia punctata_) burrows in the wall of the small intestine and causes caseous nodules in the mucous lining. This parasite sometimes occurs in very large numbers in the intestines of cattle in certain sections of the country, and apparently does considerable damage.
_Nodular disease_ of the intestine, due to young nodular worms which burrow in the intestinal wall during a certain stage in their life history, sometimes apparently produces serious effects, particularly in young cattle, but commonly has little or no perceptible influence on the general health. It, however, often renders the intestine unfit for use as sausage casings, and as it is widely prevalent among cattle the loss from this source is considerable. The greenish or yellowish nodules with cheesy contents are frequently mistaken by the inexperienced for lesions of tuberculosis.
The life histories of the various small roundworms occurring in the intestines of cattle, so far as they have been worked out, are very similar to that of the twisted stomach worm as described on page 519.
_Treatment for intestinal roundworms._--The preventive measures are similar to those recommended in the case of the twisted stomach worm (p. 521).
Medical treatment is generally not very satisfactory. According to the Oklahoma Experiment Station, the addition of 1 per cent of tobacco to the bluestone solution used in the treatment of stomach worms in sheep is effective in the removal of hookworms. The bluestone and tobacco mixture described on page 524 may be of value in the treatment of hookworms in cattle. It is a.s.serted by one author that 2 or 3 drams of rectified empyreumatic oil in a mucilaginous emulsion, followed the next morning with a purgative of 1 to 1-1/2 pounds of sulphate of soda, will expel the large roundworms (_Ascaris vitulorum_).
PROTOZOA.
A number of species of protozoa have been reported as parasites of the intestines of cattle. To one species has been attributed a serious disease of cattle in Switzerland known as red dysentery, but so far comparatively few cases of this disease have been recorded in America. It is probably more common than is generally supposed. Calves particularly seem most likely to be affected.
FLUKES IN LIVER AND LUNGS.
Two species of flukes occurring in the liver and lungs are known to affect cattle in the United States. These parasites are flat, leaf-like worms; one of them, the common liver fluke (_Fasciola hepatica_, fig. 19), is less than an inch in length, while the other, the large American fluke (_Fasciola magna_, fig. 20), is considerably larger when full grown. In their life history these flukes depend on snails as intermediate hosts. At a certain stage of development the young flukes leave the snails, become encysted on stalks of gra.s.s (fig. 21), or fall into drinking water, and finally may be swallowed by cattle. Stiles writes as follows:
Flukes may produce a serious, often fatal, disease, more especially in younger animals. The symptoms are somewhat similar to those produced by worms in the stomach. The first symptoms are generally overlooked, the disease not attracting attention until the appet.i.te is diminished; rumination becomes irregular, the animals become hidebound, and the coat dull and staring. The staring coat is due to the contraction of the muscles of the hair follicles. The visible mucous membranes become pale, eyes become dull, there is running at the eyes, and the animal gradually becomes emaciated. As the disease advances the milk supply is lessened, fever appears, there is generally great thirst, but the appet.i.te almost ceases; edematous swellings appear on the belly, breast, etc.; diarrhea at first alternates with constipation, but finally becomes continuous.
The disease lasts from two to five months, when the most extreme cases succ.u.mb.
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.
[Ill.u.s.tration: FIG. 19.--The common liver fluke (_Fasciola hepatica_).]
[Ill.u.s.tration: FIG. 20.--The large American fluke (_Fasciola magna_).]
[Ill.u.s.tration: FIG. 21.--Portion of gra.s.s stalk bearing three encysted cercariae 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 b.a.l.l.s, 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.