DISEASES OF SHEEP

New Zealand Herald, Volume LXXI, Issue 21874, 9 August 1934, Page 5

DISEASES OF SHEEP

CAUSE OF LIVER-FLUKE SYMPTOMS AND TREATMENT nv H.n.T. On considerable areas of sheep land in Now Zen land, and particularly in tlie North Island, stock frequently becomes a fleeted with liver-fluke. 1 hese areas are either low-lying and swampy, or arc badly-drained hill country where there are swampy basins or boggy creek-bottoms. Research has proved that the flatworm. which causes the disease, spends a part of its life cycle in a small tresh water snail, (Limuaea trumcatula.) Through these snails, eaten by the sheep with the grass to which they are attached in these swampy areas, the minute Jluke is introduced to the sheep's system and passes unharmed to the intestines, where it bores through the thin membranes, enters the blood stream, and is carried to the ducts of the liver. The first effect of liver-fluke infection is to stimulate the action of the liver, presumably bv irritation, and the increased flow of bile both fattens the animal rapidly, and at the same time sets up an obstinate purging or scouring, which does not respond to the usual corrective medicines. The skin will be found to have lost its bright, healthy tint, and may have become dappled with yellow spots, while the wool is readily pulled out Draining and Spraying It is obvious that the breeding grounds of the snails should be removed bv draining, but where this is impossible. as is often the case, considerable reduction of the snails can be effected by spraying the infested areas with a half per cent solution of copper sulphate, or by broadcasting fine dry copper sulphosphate. Another method of ridding running water-courses of the snail is to put several lumps of copper sulphate (Milestone) in a bag at the source of the stream, and renew as it slowly dissolves during the warm autumn weather. Measures to prevent the sheep becoming infested on country known to be " flukey " are to drench them at regular intervals with bluestone as commonly used for intestinal worms. Another'effective preventive drench, if given to sheep which have been starved over-night, and drenched at least once a week, is nitre (salt petre) 60z., copper sulphate 30z., salt 31b., and boiling water three gallons. Mix in a crock, or tub,'and when milk-warm add 3oz. of turpentine. Stir well and give in two fluid-ounce doses. Effect of Humid Weather

In spite of the most careful drenching, however, sheep will become affected when conditions are particularly favourable, especially in humid autumns. When, therefore, it is obvious that sheep have become infested, no time should be wasted before dosing them with carbon tetrachloride. This is now procurable at reasonable cost and can generally be relied upon to effect a cure if serious damage to liver has not already resulted.

The invasion of fluke's may pave the way for the entrance, to the sheep's system of far more deadly germs, which the sheepman has less chance of fighting successfully. Ono of the most deadly of these germs which invades the fourth stomach of the sheep is a bacterium known as " Vibrion septique," the primary cause of the deadly disease known as braxy. It is claimed that in New Zealand we have 110 actual braxy, and that our " braxy-like disease," which so closely resembles it, is the result of the invasion of another bacterium of very similar characteristics. However this may be, the mode of entry, symptoms and inevitable result are so similar that for practical purposes they may be considered identical. • When the braxy bacillus is present in the fourth stomach —usually in autumn or early winter —it cannot gain entry to the blood stream unless a perforation of the membrane is first effected by one of the boring parasites. About this time the sheep is also being attacked by the liver-fluke worm, but before the effect of the latter is seen the sheep is usually dead from braxy. Symptoms of the Trouble The symptoms, when noticed, are a short, quick step, a cessation of feeding, restlessness and uneasiness, with a tendency to lie down and get up suddenly. Latterly there is a separation from the rest of the flock, a more or less dazed appearance and a disinclination to rise when disturbed. Finally there is an inability to rise, and soon death supervenes. One of the most recent methods of treatment is the administration of a culture of the braxy bacillus by the mouth during February when the bacterium is not at a virulent stage. This appears to enable the animal to resist a later virulent attack. A second, and possibly more effective, treatment is to innoculate the .stock twice with increasing doses of a prepared vaccine. The first dose gives the animal a certain immunity which enables it to withstand a larger dose in a fortnight's time.