PARASITES IN SHEEP.

New Zealand Journal of Agriculture, Volume XIII, Issue 3, 20 September 1916, Page 226

PARASITES IN SHEEP.

A. M. PATERSON,

M.R.C.V.S., Veterinarian.

Most farmers have doubtless observed that' foals harbouring lice became rapidly clean when given good nutritious food — dressing or medicinal treatment of any kind being required. Exactly the same thing happens with • sheep infested with internal parasites of various kinds. Good nourishing food given to sheep or lambs harbouring parasites in the form of worms will, in almost all cases, effect recovery. This is a clear indication that had the sheep 01- lambs been getting good food all along they would probably not have become the victims of intruding parasites, which seem to be always waiting to enter, the bodies of animals whose vitality has been lowered by any cause.

The moral, then, is to keep up the vigour and vitality of the flocks by giving them a sufficiency of good, wholesome food all the year round. Sheep as a rule do well in the summer-time. They are then being fed wholly by nature. • In the winter, however, when we have to make up nature’s deficiencies, • they do . not always fare so well. It is then that we may discover that our system of management falls very far short, of what it ought to be. Particular' care should be taken not to confine sheep for lengthened periods to swampy areas which yield only indifferent feed. Nor should sheep be kept on good paddocks ■ until

the feed has become so fouled that it is repellent to them Overstocking, of course, leads to exactly the same results.

Of the many parasites that affect sheep only two—lung-worm and stomach-worm—will be touched upon in, the present notes. In the early days lung-worm seems to have been looked upon as one of the chief causes of mortality in sheep in this country. One judges this to be the case from the fact that even to-day it is usually suspected by farmers in any outbreak of disease in a flock, especially ’if some of the sick sheep cough a little. But as a matter of fact this parasite is far less dangerous than the stomachworm, and my experience is that improper feeding - conditions, followed by trouble set up by the stomach-worm, are responsible for enabling the lung-worms to multiply and cause their part of the trouble. It would be well if farmers could transfer that keenness they habitually exhibit towards the lung-worm and concentrate it on this other parasite, . the stomach-worm; for it, and not the lungworm, is the sheep’s greatest enemy.

When sheep begin to show dullness and weakness accompanied by “ black scour,” if at the same time they are coughing, and one is inclined to think the cause of the trouble is lung-worm, even if the lung-worm has been seen coughed up from the lungs or sneezed from the nostrils of the affected sheep, the stomachworm should be suspected. Let the farmer’s energies be exerted in carrying out a line of treatment that will destroy or remove this parasite, and it will be exceptional if he does not get better results than he has usually obtained in treating such cases for lung-worm.

Assuming, then, that a flock is suspected of being affected with this stomach-worm, the first thing to do is to supply the sheep with some supplemental food. The best that can be given is crushed oats , and bran, allowing about 5 oz. of the mixture for each animal. Having got the whole flock on to the food prescribed, the affected animals should now be treated' medicinally. Lysol, given in the proportion of one teaspoonful (one dram), for every three lambs and the same quantity for every two sheep, is as good an agent as is likely to be at present available. To give lysol pure would be disastrous; to give it insufficiently diluted would be dangerous. Each dose must therefore be mixed with a suitable quantity of milk or water, but preferably milk ; and about 6 oz. of the mixture is found in practice to be sufficient. The chemist who supplies the lysol might be asked to figure out the proportions for the number of sheep to be treated, so that there will be no risk of mistakes, accidents, ,or ■ waste. One dose will, as a rule,

be sufficient, but in some cases two or more may be required. Allow a day to pass . before repeating the dose. .4

All sheepowners should furnish themselves with a suitable drenching-flask -for this kind of work. One of the best is made of tin, is shaped like a long-necked bottle, and has a capacity of about 8 oz., but a hole on one side prevents it holding more than 6 oz. When dipped into the vessel containing the drenchingmixture it is filled to the top, but on raising it perpendicularly all but the required amount pours out at the hole referred to., A finger or thumb is then placed on this hole and the dose administered' in the usual way. In drenching sheep ' and lambs, at the same time, two separate vessels, must be used to hold the drenching-mixture—one for the sheep, the other for the lambs.

When drenching keep the sheep’s head straight in line with the body, and do not tilt the head too high. If the head is raised too high the animal will not swallow readily, and in the endeavour to make it swallow it may be choked. If an operator will try to perform the act of swallowing with his own head thrown far back he will realize what is meant.

For fuller information on the subject of stomach-worms in sheep the reader is referred to the Department’s New Series Bulletin No. 3, “ Parasitic Gastritis of Sheep.”