The Station.

Otago Witness, Issue 1489, 29 May 1880, Page 6

The Station.

THE CAUSE AND CURE FORGOT IN SHEEP.

The Experience of Mr Eobert Wallacr, op New Brunswick, as given in thk Agkicoxtctral Gazette.

When an amateur Btudent with Professor Williams, Prinoipal of the new Veterinary College, Edinburgh (says Mr Wallace), I interested myself in diseases whioh oause loss to stockholders, determining to carry out the simple and rational treatment recommended for rot, amongst others. My first opportunity was in the case of a Blackf aced (Highland) ewe, bo much reduced that she had to be assisted in rising. I had one ounce of common Bait given to her daily, which she ate greedily, and became very fond of, but would never take more. The symptoms of rot soon began to disappear, and in three months the desired normal state of health was restored, and the ewe went off to be fatted, I next bought seventeen ewes, Cheviot and Blaokfaced, and so weak were they with the disease that I had them carted home. In addition to as much salt as they would eat twice a day, I added decorticated cotton cake, ground small , beginning with little up to half a pound each day. They were thus fed through winter, until sufficient grass came, when the treatment was discontinued. Fifteen went off prime fat about the Ist of August ; one broke in among rams, and had a lamb ; another not fat enough was left as the "shot," but quite healthy to all appearance. The fate of this one may be instructive, This winter the salt was not administered, and It ultimately died of rot, The theory

as to how salt is efficacious, is not that it destroys directly the flukes found in the liver ducts, but that it makes away with the eggs— at least to a great extent— which are found in vast numbers in almost every part • of the body, in the digestive system, and even circulating with the blood. If the treatment is continued long enough, the flukes die a natural death; and if there be no eggs to ultimately (on maturing) take their placeß, the animal will become free of the pest. We cannot always hope to secure a permanent recovery, as the fate of one of my sheep showed j but if we have the numbers reduced to a minimum, it is all that is necessary. It is well known that flukes can be found in the livers of almost every sheep «'V from some mosß farms in Galloway, but do no harm to ninety-nine out of every hundred, and only when in large numbers. The sequence of changes in the animal system is originated by irritation, and consequently inflammation, beginning in the biliary ducts, and extending through the liver, preventing it performing its proper functions to aid digestion ; the stomach then gets disordered, imperfect blood is the result, and time is all that is necessary to exaggerate the consequences into a persistent anaemia, ending in death. Perhaps at this time a Bhort account of the different stages through which the liver fluke (Distoma hepaticum) passes in its progress of development may not be uninteresting. The egga are voided by sheep in immense numbers with their excrement (one fluke sometimes produoing 40,000), and get washed into pools of water, and hatoh as it were. They burßt at one end, and ciliated embryos come out and swim rapidly about, gradually elongatbg, the cilia fall off, and oreeping larvro are left in the form of little sacs, cylindrical at one end, and flattened ' out at the other into a tail and two winglike projections. These somehow gain access to the bodies of snails, styled intermediate bearers, and when fully matured in this form are called Radiee. These are capable of produoing within themselves like formß (Cesarise), but which have no power of generation, and drop into the water, where they for a time have an independent existence, boring at last into the body of a second intermediate mollußoan host, losing their tails and inoysting themselves under the skin. On developing into the pupa state they again appear in the water, and are drunk up by sheep or cattle, or taken in with the short sweet grasses on wet bare pasture. The gastric juices digest the sac-like coverings, and the pupse are set free ; they may also be taken, into the alimentary banal in the . form of Cercari» (Sir WyvUle Thomson). We next find the perfect worm in the liver ducts, causing that irritation which often ends in all the symptoms of rot, laying eggs by the tens of thousands, again to go through the same wonderful cycle. These worms are seldom more than an inch long, we ,broad, thin, and flat, attaching themselves by a suoker on the under surface. Sometlmeß hundreds have been found injthe liver of one sheep. t > , • : .< ,, I was amused at the way Professor Simonds, in bin esßay on "Rot in Sheep," floored, indiscriminately and without mercy, the attempt of every writer of note, ancient or modern, who tried to do anything in the way of proposing a treatment for rot, and expected at least to have some sort of feasible courße recommended that would suit all olasses interested. Hill farmerß, or, in other words, large sheepowners, must feel thoroughly disappointed, and look upon the Buseeßtionß, to say the least of it, as absurd. How could a man with 3000 or 4000 sheep, who would save them from rot, thoroughly . underdrain all his wet lands ?or why shquld he when it has been proved that surface drainß serve the purpose quite as well? How would the same man '•well protect sheep in seasons of excessive rainfall ?" or 11 provide for their nutrition by supplying them with a rich and generous diet, fleshforming and heat-supporting in proportion to the demands made on the system"; or, finally, administer " such medicinal agents," etc, etc., as are recommended. If neither labour nor expense were factors in the calonlatioß, it might be all well enough, but what the farmer wants is, a . cheap easy method of doing the best thing for prevent ing, as well as arresting, the progress of the disease, or it may be ultimately curing it. I fsel confident this is to be found in the simple salt treatment described. I claim no credit as to originality in the matter ; all T did was simply to carry out a successful experiment, cased on scientific principles recommended to me. With the single exception of eweß in lamb, salt maybe given ad libitum, as, when taken voluntarily, Bheep will not consume it in any quantity to do harm. Mine would never take more than one ounce a day, even although coaxed by the addition of cotton '•ake. Sulphate of iron is recommended iD treatment, and, although good, does not seem to be necessary with Bait. Other preventives are directed mainly against the conditions favourable to the existence of mails, which act as intermed ; ate hosts. Among these are surface and under drainage. In Scotland, since open sheep drains have been so generally introduced, rot in most districts has entirely disappeared, while it has been reduced to the merest minimum in those in which it still lingers. As to liming and sowing of salt on land, the latter has been deprecated by some, mistaking the reason it is applied for — a direct attack on the undeveloped forms' of the parasite. In this country we do not half appreciate the valne of salt, either as a relish in the food of our animalß, or as a manure. When travelling in Canada last fall, I found some of the most intelligent farmers applied it to their crops in the same way as we would dissolved bones. Of course, we are nearer the sea than the central parts of Canada, and get so much of the neosssary salt from that Bource, yet we have not enough naturally, from the large percentage of salt in the ash of blood, it is plain it must be most neoessary to the animal, and consequently to plant life. I will just mention, in closing, that in the time of our grandfathers the treatment for rot in this country was to pour into each affected sheep a quart bottle full of salt and water, whiob. was said either to kill or onre. The killing would depend much on the quantity of salt used, as compared ' with the strength of the sheen to withstand ta Ratios,