THE BLOW FLY.

As has been said, the shepherd should see the sheep every day, and indeed in Scotland upon the hill pastures, the shepherd aims to see each member of the flock twice every day. One of the terrors to which they are exposed is that of the blow fly, which, finding some foul or wet spot upon the wool, deposits its eggs. These hatch and crawling down next the skin the maggots gnaw until they have caused a watery exudation from the irritation, and set up an odor that at once attracts more flies, so that in a short time the poor sheep is a terrible object, having a great patch just beneath the wool filled with myriads of hideous, wriggling maggots. Sometimes where the spot is within reach of her mouth she will tear off the wool and in a measure rid herself of the pests, but more often the trouble spreads until the poor beast is literally devoured alive. The prevention is to shear early and to have a clean place for the sheep to lie in the cool shade during hot summer days, to see that no part of the body becomes fouled and should she, from violent rain, become wet enough to be struck by maggots, to promptly rout them by the application of turpentine, or pouring on a quantity of sheep dip as though treating scab. The unfortunate sheep should not, however, be permitted to go away from the sight of the shepherd for a few days, lest the flies re-infest the same spot before it has entirely healed. When lambs' tails are docked late in spring there is danger of the same trouble there, so that they should be coated with pine tar upon the stumps and then given careful watching for a few days.

PREVENTION OF PARASITES.

While the writer feels that all the cautions he has endeavored to give have been well deserved, yet in his estimation, all of the other dangers to which the flock is subject pale into insignificance when compared with the danger of infection from internal parasites. These have wrought more ruin to American flocks upon arable farms than have all the dogs, politicians, scab germs, tariffs and blow flies put together. And it is safe to say that a shepherd who once masters the question of internal parasites and learns to keep his flock always free of them will find his other troubles trifling, and remain in the business content with his profits and deriving great satisfaction from his occupation. Whereas, the unfortunate shepherd who does not believe in parasites, or believing, neglects to do as well as he knows, will be doomed together with his flock to much sorrow, tribulation and loss. Sheep are subject to a large number of internal parasites, although but two or three give sufficient trouble in our land to deserve attention. These are the nodular disease, tape worm and the stomach worm (Strangylus Contortus.) Of these the last and smallest is easily the most deadly, and has wrought damage in the United States of millions of dollars in the past, and is to-day continuing its unseen but deadly work. The nodular disease is caused by a worm which inhabits the intestines and attacking their walls, deposits eggs in the tissue about which a little swelling or tubercle is formed, called a nodule. This nodule has in it a greenish, cheesy mass in the midst of which the young germ is developing. These nodules spreading over the surface of the intestines diminish their power of absorption and finally with

interference in assimilation and digestion, work great injury to the sheep. The nodule disease does not spread with great rapidity through the flock, but once having foot-hold, continues to increase steadily from year to year until at last so much infection exists that profit is no longer possible from that flock. It causes the condition known to butchers as "knotty guts," which unfits the intestines for sausage casings, and the packers will tell you how few of the eastern grown sheep sent to market are free of this trouble. Treatment for the nodular disease is quite impracticable, owing to the position of the encysted parasites, and prevention the only feasible course in fighting them. As the prevention of this trouble will be of a similar nature as that for the prevention of stomach worms, we will consider them together.

THE STOMACH WORM.

The stomach worm is a tiny hair-like worm about three-quarters of an inch in length that inhabits the fourth stomach of sheep. No one should permit a sheep or lamb to die from any unknown cause upon his farm without promptly dissecting to ascertain the reason, and in this dissection, search through the tract of the alimentary canal will, in ninety-nine cases out of a hundred, reveal the cause, Beginning with the paunch or largest receptacle of food, which is in the nature of a storehouse where quickly gathered food may be held, until re-masticated, and passed on, the operator should seek for evidence of impaction, or for the presence of foreign matter in some cases, such as hair balls, wool or possibly nails, although these are more apt to be found in cows. Passing on now from the paunch through the other stomachs the operator must scan very closely the contents of the fourth stomach just where it joins to the intestines, and here swimming about in the dark colored fluid found therein he will probably find from a few to a myriad small wriggling worms. Their appearance is altogether too insignificant to explain the great havoc that they work, but there is no doubt of the results they are capable of achieving in the ruin of the health of the sheep, and especially of the young lambs. Having passed the fourth stomach the intestines may next be examined for the little bluish "knots," or nodules upon their surface, and then search may be made for tape worms, which are, however, rare visitants of any flock while fed upon pumpkins as described earlier in this bulletin.

The work of the stomach worm, however difficult it is for us to understand, is very disastrous to the lamb or immature sheep, and does quite sufficient damage to mature ewes so unfortunate as to be afflicted. The first symptoms of infection will be a general loss of thrift with a paleness about the eyes and depraved appetite, perhaps ceasing to eat or else eating ravenously at times, and a desire for abnormal articles of food such as rotten wood or earth. If the shepherd will catch the sheep and part its fleece and observe the skin, he will find it pale and chalky, which fact has given the disease the name of "paper skin." This paleness, however, is but a symptom of the general anemic condition of the animal, and is not at all the seat of the disease. The natural progression of the disease is from one stage of debility to another until death comes to end the strife, although when a less degree of infection exists it will simply cause a loss of thrift and profit

Prevention of the stomach worm parasite is not difficult, but the violation of certain laws of management for even a few times during the summer may bring disaster. It is not certainly known how long these parasites exist within the body of the sheep, but at some time they mature and being filled with eggs about to be hatched pass out and fall on the ground. Now it is not definitely known how long these remain upon the ground alive before they must again find entrance into the body of another sheep or lamb. It has been thought they might live a year or more upon the pasture, possibly, within the bodies of earth worms, but later experience seems to indicate that the time elapsing between the expulsion of the young germs from one sheep and its entrance into the stomach of another is of comparatively few days' duration. The stomach worm is carried over winter in the stomachs of the mature ewes, by them dropped upon the grass in early summer, then taken into the stomachs of the lambs as they crop the short, sweet grass that naturally grows where many of the droppings are deposited, and thus its life cycle goes on. It has been stated with some degree of reason that a temperature of 50 degrees is fatal to the stomach worm lurking in the grass or upon the ground. This fact, if it be true, would explain the ability of Scottish shepherds to maintain for centuries great numbers of sheep upon their thickly sodded mountain pastures without loss from these parasites. In American pastures, however, between the 10th of May and the beginning of October, the ground would seldom get as cold as 50 degrees, therefore, between these dates infection is easy and results correspond with this theory. In southern England the shepherds must always be on guard against this parasite, which they do by seeing to it that the lambs do not graze behind their mothers, but have always a fresh bit of grass hurdled off for them on which they run forward, the ewes following the next day and consuming what the lambs have left. In Dorsetshire, an old shepherd told the writer that lambs must never sleep two nights upon the same ground. This same old shepherd had set hurdles about a great oak tree so that the sheep could not go beneath it, this being in permanent pasture and the sheep dry ewes. Upon being asked the reason for these hurdles he gave a characteristic answer, showing his knowledge of facts but his ignorance of the true theory thereof. "The sheep do love to lie be neath the tree, sir, and the wind do blow and the draft makes them cough, sir." The real truth being that beneath this tree with the constant accumulation of infected droppings, green grass sprang up thick and sweet and sheep grazing it rather than go out into the sunny open would take in many parasitic germs which would cause them to lose thrift and to cough. In our own land the prevention of infection from stomach worms consists, as has been directed, in having the lambs born early enough so that they may mostly go to market before the danger period has set in, and for those that are to summer upon the farm, the separation as early as practical from older sheep and putting them alone upon fresh pastures either of crops especially sown for them or upon grass that was not grazed by another sheep for some months previously. This treatment will surely ward off the insidious foe of the stomach worm. There is another point in summer management that works toward good health in the

flock and that is to encourage the ewes to shade in the barn or some cool, airy, dark shed, rather than to shade under trees or along fences, thus during our summer heats when the period of danger from infection is worst they early seek the shelter of the barn and deposit all their droppings there, and do not infect the grass as they surely will if they shade promiscuously beneath the trees or along stone walls or fences.

Perhaps the most practical method of warding off the attacks of parasites, is the pasturing of sowed crops, such as oats or rape, or a mixture of the two, or the pasturing of alfalfa sown with brome grass (bromus inermis). Any one of these crops is usually bitten off higher up from the ground than is blue grass or white clover and therefore there is much less danger of taking an infection. The writer after many seasons pasturing of alfalfa has never had a single case of infection arising among the sheep thus treated. A surer method of prevention consists of confining the lambs to an airy barn, basement or shed and soiling them with green crops cut and fed fresh every day. This method is really much more practical than might at first be supposed, seeing that from a given area much more feed is secured, and many more animals may be kept thus than when they are allowed to run over the fields, eating too closely in spots and wasting other spots by trampling it down. The writer has seen in France great numbers of sheep kept upon the larger estates in the central valleys near Paris, by this system of soiling in their great, cool, airy, stone built sheds. The sheep eat from racks, green clovers with the bloom on, straw threshed fresh every morning, of which they consume little save the weeds and leaves upon the stalks, a small amount of roots with possibly a taste of grain. Wonderful is the thrift of these flocks, and never a trace of parasitism anywhere, although the climate and luxuriant vegetation would as certainly invite parasitic attacks as in our own land. Something may be accomplished by treating the ewes before going to pasture by ridding them of the egg-bearing worms that would otherwise infect the ground. Several systems of medication have been advocated and nearly all of them abandoned, so that at present we seem to be given choice between two things, the use of coal-tar creosote and gasoline. Circular No. 35, of the United States Department of Agriculture, Bureau of Animal Industry, by Ch. Wardell Stiles, Ph. D., Zoologist of Animal Industry, contains a valuable account of treatment for these parasites, from which we quote:

COAL-TAR CREOSOTE.

"I have had excellent success in treating sheep, goats, and cattle for the twisted wireworm (Strongylus contortus) with a 1 per cent. solution of coal-tar creosote. The medicine is easily prepared and quite inexpensive. It may be purchased of the druggist in small quantities of one ounce, or in pound bottles. One ounce is sufficient for about 20 adult sheep, and the cost of the treatment is less than one-half a cent per head; if creosote is purchased by the pound, the cost is reduced to less than one-quarter of a cent per head. If creosote is called for at a drug store, beechwood creosote will usually be dispensed. This is more expensive than the coal-tar creosote and not so satisfactory in expelling worms.

"A 1 per cent. solution of coal-tar creosote is made as follows: Coal tar creosote,

Water,

99 ounces 6 pints and 3 ounces.

.. 1 ounce.

99 ounces.

"Twisted wireworms (Strongylus contortus) taken directly from the stomach of sheep or cattle die in one-half to one and a half minutes when immersed in this solution.

"If, in dosing, this liquid enters the lungs the animal may succumb in a few minuats. If the dosing is performed carefully, as much as 6 2-3 ounces may be given to a full-grown sheep without fatal results. In some cases, however, the animal shows ill effects, from which it usually recovers within half an hour. Six ounces were given to a number of sheep without the slightest ill effects. The following table gives the doses of the 1 per cent. mixture which were used in about 400 cases without ill effects:

Lambs, 4 to 2 months old, 2 to 4 ounces (about 60 to 120 c. c.) Yearling sheep and above, 3 to 5 ounces (about 90 to 150 c. c.) Calves, 3 to 8 months old, 5 to 10 ounces (about 150 to 300 c. c.) Yearling steers, 1 pint (about 480 c. c.)

Two-year olds and above, 1 quart (about 960 c. c.)

"Sheep, goats and calves which received this treatment showed a marked improvement a few days after receiving a single dose. In experiments with creosote at Washington, D. C., sheep were drenched with a 1 per cent. solution and killed immediately afterwards. Upon opening the fourth stomach, it was found that the wireworms present were dead. In some cases where this was tried later, the wireworms were found to be still alive; but it is believed that the explanation of this fact has now been discovered (see below page 59.) Creosote does not appear to have much effect upon the worm below the stomach.

"If an overdose is given by mistake, and if the sheep appears severely affected by it, the animal should be placed in the shade. Even in some cases of very severe overdoses, where the animal is given up for dead, practically, it may entirely recover within an hour or so

COAL-TAR CREOSOTE AND THYMOL.

"If, in addition to the stomach worms, the animals were suffering from severe infection of bowel worms, such as the hook worms, better results were obtained in the treatment when powdered thymol was added to the creosote. In cases of this kind, the creosote solution is prepared, as directed above (page 1), and 30 to 80 or even 100 grains of thymol added to each dose after it has been measured. "Thymol is expensive, the price varying in different parts of the country. It may be purchased by the ounce, but it is considerably cheaper if purchased by the pound. Avoid using thymol which has become yellowish or reddish and which has run together in the bottle so as to form a solid mass. Powder the crystals and have the druggist measure 30 grains. Give 30 grains to a lamb, about 50 grains to a yearling, and 70 to 80 or 100 grains to older sheep, according to size. In experiments I have had excellent results with a single dose of the creosote and thymol mixture. If necessary, however, the dose could be repeated after a week.