THE LUNG-WORM OR ROT IN SHEEP.

New Zealand Mail, Issue 1107, 19 May 1893, Page 5

THE LUNG-WORM OR ROT IN SHEEP.

(By A.L,, Written for the New Zealand Mail. The following information may be of service to the inexperienced, who may be unfortunate enough to get lungworm or rot into their flock. FIRST, AS TO THE DISEASE. The rot in sheep is occasioned by the fluke (in excess, a parasite fin to 144 n in in length, and jiri to £in in greatest breadth. The head is of a pointed form, round above and flat beneath, and the mouth opens laterally instead of vertically. There are no barbs or ternacula, as described by some authors. A great number of oval particles, hundreds of which, taken together, are not equal in bulk to a grain of sand (and of a pale red colour), and supposed to be the spawn or eggs of the parasite, are found in the intestinal canal, and from November to April (May to October corresponding months in New Zealand), may occasionally be seen in the lung of the healthy Fheep, swarming in ,that of the diseased one, and particularly the rotted sheep. There can be no doubt, the eggs are frequently received in the feeding off the grass, for, says a writer in a Bath paper, 'On killing a sheep, I examined the viscern carefully, and in some of the passages leading from the liver, and which appeared turgid, I found a whitish, thick liquor, which appeared to be all in motion. On applying a pocket-glass, I found it to contain hundreds of these flukes, which were apparently just hatched, and about the' size of mites. These, if the sheep had not been killed, would probably have soon obtained their usual size and destroyed the animal.' Leenwenhoeck says that be has taken 870 flukes out of one liver ; in other cases, and where the nheep had died of the rot, there were not found more than ten or twelve.

Of the first outwaid symptoms of this disease; if in warm sultry weather, sheep that are grazing on low and moist land, feed rapidly, and some of them die suddenly, there is reason to fear that they have contracted the rot : this suspicion will be further increased if in a few weeks afterwards the sheep begin to shrink and become flaccid in their loins. By pressure about the hips at this time a cracking is sometimes perceptible. Now, or soon afterwards, the countenance looks pale, and upon parting the fleece, the skin is found to have changed its vermillion tint for a pale red, and the wool is easily separated from the pelt; as the disorder advances the skin becomes dappled with yellow or black spots. About this time the eye loses its lustre, and becomes white and pearly from the red vessels of the tunica adnata, and eyelids being contracted or entirely obliterated. To this succeeds debility and emaciation, which increases continually till the sheep die, or else ascitis, or perhaps general dropsy supervene, before the fatal termination. To the above might be added the internal symptoms, but I will now turn to THE CAUSE. Dr Harrison, of Lincolnshire, wrote :—' No flockmasters are perhaps more anxiously alive to the disease than the owners of the noble watermeadows of the south of England. These excellent farmers have noticed that the first crop of spring-water meadow-grass never imports the rot to sheep ; but that the second crop (which they ; therefore make into hay), is almost certain to do so. They notice, also, that the worst rotting time is from midsummer to michaelmas ; that almost all meadow land, ifchanceflooded

in summer, that is, if covered by the overflowing of rivers, so as to be covered by their muddy waters, is almost certain to rot the sheep, that gravelly-bottomed water-meadows, never rot the sheep fed on them, in any season or period of the year. This would appear to confirm the very common suspicion that it is not the grass which rots the sheep, but the gaseous or acqueous vapom-s which emenate from such places, move copi* ously as the weather becomes warmer in the summer.'

Another authority said the disease does not arise from deficiency of food ; a sheep may be reduced to the lowest state of condition—he may be starved outright, but the liver would' not be necessarily or often in a diseased state. Thousands of sheep are irreparably ruined by scarcity and bad nourishment, but the symptoms of their disease bear no affinity to those of rot. The rot in sheep is evidently connected with the soil or state of the pasture, it has reference to the evaporation of water and to the presence and decomposition of moist vegetable matter. Some seasons are far more favourable to the development of the rot than others, after a rainy summer, or a moist autumn, or during a wet winter, the rot destroys like a pestilence. A return and a continuance of dry weather materially arrests its progress. Theieis something more than moisture necessary for the production of the rot, the ground must be wet, and its surface exposed to the air, and then the plants previously weakened or destroyed by the moisture will be decomposed ; and in that decomposition certain gases or miasmatic will be developed, that cannot be lons breathed or scarcely breathed at all by the sheep, without breathing the rot.

The mischief of the disease is effected with almost incredible rapidity. A sheepbreeder on the Downs of Dorset had a block of 800 sheep, the shepherd took them to a sort of basin of water (about | an acre in extent) and let them drink, but upwards of 200 of them became rotten. Another grazier had a shallow piece of water (1 g- acres) he decided on draining it, but imperfectly did so, and immediately afterwards his sheep became liable to the rot.

In a rotting year, if the land is understocked, and thus the ground remains protected by the herbage, the loss of the farmer will not be immense, but if the field is overstocked, and consequently trodden down and poached, the rot will probably assume a most fatal character. Another authority writes, rot was connected with excess of moist food, and low wet situations, foreign to their natural habits, for sheep in a state of freedom seek the most elevated, dry, healthy situations; in a state of nature, too, they browse upon health plants and seek with avidity at certain periods salt springs and salt exudatious facts, which have not escaped flockmasters ; the wild sheep of Siberia, which are the presumed origin of all our domestic sheep, are found on the immence chain of mountains of Asia, where they remain until the approach of winter.

Fitzherbert, who wrote over three centuries past, ' that moorish grounde and marsche grounde and flouded grounde from the fylthe the siycheth uppon it. were thynges that rotteth shepe.' The experience cf other English sheepowners might be quoted, but I will now consider THE CURE as to the land if wet, drainage imperative and complete; imperfect drainage will not answer; of the food, something further than green grass all the year round is wanted. Shrubs, herbs (parsley good) or hay some part of the year is necessary ; as medicine, spirits of turpentine and salt; the latter was held in high estimation as a preventative and cure ; rock salt will answer the purpose.

For the bulk of the above information I am indebted to high and departed authorities, the knowledge gathered by them from years of observation.

Seasonable work is more effective than unseasonable work. The weed is most easily killed when it is smallest. As early impressions are the strongest, an animal can be trained with a fraction of the effort required later. The clod is most easily crushed while freshest; every day of sun and wind increases the labour necessary to make it a fit bed for the seed and the plant.