SHEEP AND CALVES

Otago Daily Times, Issue 23631, 15 October 1938, Page 3

SHEEP AND CALVES

PROBLEM OF INTERNAL PARASITES DIAGNOSIS AND TREATMENT VALUABLE REMEDIES AND DRENCHES The annual mortality amongst hoggets from internal parasites is increasing from year to year, and on some properties is assuming enormous proportions. Similarly, losses amongst calves are proportionately high. This article is intended to discuss various Important aspects of the problem and to give the available information both for the treatment of sheep and calves. Correct Diagnosis The fact must be faced that graziers spend large amounts of money on the purchase of drenches which have no efficiency whatsoever against the parasite they are attempting to eradicate. They acquire, furthermore, a false sense of security brought about by this heavy expenditure Consequently, where sheep are suffering from internal parasites, both from the symptoms they exhibit and a postmortem examination, a farmer should attempt to diagnose the cause of the trouble for himself. Conducting a Post-mortem It is not very difficult on postmortem to demonstrate at least a few worms, but that this does not mean a great deal is borne out by the fact that practically all our fat lambs going through the works carry a small number of parasites with them. This is less incredible when it is realised that, on the average, a hogget harbours 10 or 11 of the possible 18 varieties with which it could be infected. It is obvious now that two important questions arise in the mind of the reader:— (a) Which parasites are definitely harmful? (b) How many of the harmful variety must be present to cause the death of the animal? From our existing knowledge there are three, and sometimes four varieties which are a source of trouble, excluding fluke in the Hawke’s Bay

area. Of the four varieties, two affect hoggets only, and two affect all classes of sheep, especially lambs, lambing owes, ewes with lambs at foot, and broken-mouthed ewes. The small intestinal worm is popularly known as the “ black-scour ” worm, and found in the first 15 feet of the small runners and occasionally in the fourth stomach. It measures from an eighth of an inch to a quarter of an inch, and is found adherent to the walls of the bowel, where it can be seen by holding up the opened runner to the sun. stretching it between two hands. It affects only hoggets, and is the chief one responsible for the annual hogget mortality. Furthermore, only one drench has any efficiency against this parasite, and is at the most only partially effective. As regards the number necessary to cause the death of an animal 10,000 to 20,000 must be present. The medium stomach worm is found entirely in the fourth stomach particularly towards the narrow end. which joins the small runners. it measures up to half an inch and is usually brownish-red in colour. Although of less importance than the previous parasite, only 8000 to 10.000 are necessary to cause the death of an animal. The large stomach worm Is also known as the “ barber's pole ” worm, because of the red and white spiral markings on the female, which measures up to an inch in length, the male being slightly smaller, This is a particularly dangerous parasite, and affects all classes of sheep. Fortunately, however, a wide range of drenches have a high efficiency against it. It is found in the fourth stomach entirely, and any number over 1000 should be considered serious. The large-mouthed worm Ls becoming of more importance every year, and if the crown is opened by means of a knife or pair of scissors it will be found as a small, stout white worm, half an inch in length, clinging to the wall of the bowel and surrounded by pin-point haemorrhages where It has been clinging previously. So far, no drench effectively removes the parasite. Two or three hundred worms is a heavy infestation. Symptoms in Diagnosis The symptoms shown as a result of heavy infestation with the large stomach worm are very characteristic, due to the fact that this parasite is a notorious blood-sucker. If the wool is parted the skin is found to be lilywhite in colour and similarly the inner lining of the eyelids and the gums. Usually there is no diarrhoea, but this is not invariable. On the other hand, hoggets suffering from small intestinal or medium stomach worms have a normal pink lining of the eyelids, and also the gums are quite normal, but the skin may be a little pale. Diarrhoea is very frequently present, but if absent the droppings are soft and mushy, not necessarily staining the hindquarters. Methods of Treatment (a) Small Intestinal and Medium Stomach Worms.—As previously mentioned, there is only one mixture which has any efficiency against the two above parasites, and at the most is only about 60 per cent, efficient. This mixture is bluestone and nicotine, made up as follows, in 2 per cent., 4 per cent, or 5 per cent, strengths, depending on the size of the funnel or gun possessed by the farmer:— 2 per cent.: Dissolve 16oz bluestone In five gallons of water, and add Ifi fluid oz of 40 per cent, commercial nicotine sulphate. 4 per cent.: Same quantites of bluestone and nicotine, two gallons and a-half of , water. 5 per cent.: Some quantities of bluestone and nicotine, two gallons of water. j | j

Where lambs are weak, draft them off and give them the next dose lowest down, according to age. and repeat it in 10 days; otherwise, with a full dose, they may die. The Large Stomach Worm.—A wide range of drenches are highly efficient against this parasite, including the above bluestone and nicotine mixture, but where a farmer is treating adult sheep the nicotine should be omitted owing to its cost, and the fact that the bluestone alone will be equally efficient. Carbon Tetrachloride.—Farmers in the Hawke’s Bay area should use this drench on account of the presence of fluke in their district, because it is the only mixture with any efficiency against fluke. Single strength (one part carbon tetrachloride, four parts liquid paraffin). Dose: Adults 10 c.c., lambs S c.c. Double strength (two parts carbon tetrachloride. three parts liquid paraffin). Dose: Adults 5 c.c., lambs 2i c.c. Bluestone (Copper Sulphate) 2 per cent.: Dissolve lib bluestone in five gallons of water. 4 per cent.: Dissolve 11b bluestone in two gallons and a-half of water. 5 per cent.: Dissolve 11b bluestone in two gallons of water.

Tetrachlorethylene (equal parts with liquid paraffin). Dose: Adults 10 c.c., lambs over six months 5 c.c. . Repetition of Drenching Contrary to what is believed in some districts starvation, even for a short period, is unnecessary, but sheep should be held in yards for a couple of nours after drenching. Where used as a preventive measure, drenching should be carried out at three-weekly to monthly intervals; but where animals are actually exhibiting symptoms before drenching is started, it should be repeated in 14 days and then at three-weekly intervals. Where losses are experienced annually, start drenching at weaning time, or, if necessary, before weaning. The large stomach worm is a summer parasite, and in suitable seasons lambs may show symptoms before weaning. Points In Prevention Owing to the low efficiency of the bluestone and nicotine mixture against the small intestinal worm, it cannot be considered as the first line of attack in controlling the parasite. So far, adequate nutrition and proper pasture management are the two important fundamentals in combating the effects of this parasite, and until more effective treatment is available they must be considered the first line of defence. On the other hand, where the large stomach worm is concerned the very high efficiency of the treatment available makes this measure the primary one in any scheme of control. It should be borne in mind that every parasite which a sheep haibours must be picked up from the pasture—they do not multiply inside the sheep. Therefore, sheep management will aim at preventing sheep picking up a heavy infestation by avoiding long periods of stocking, especially on paddocks which are heavily stocked, and so heavily contaminated with parasites, Every property presents its own particular problem as far as prevention and control is concerned, but the following general principles should be borne in mind:— (1) Ewes should be treated, at least once, at three weeks before lambing in order to keep the lambs at foot on as clean pastures as possible. (2) Lambs should be weaned on to areas which have been rested or burnt off, and should be rotated as far < as possible. This becomes essential where pastures are highly improved and have a heavy carrying capacity. Over-stocking is one of the most dangerous factors in hogget mortality. . (3) Treatment should be begun at weaning time or earlier, and not left until the animals arc dying. Where trouble has been experienced one year, drenching should be started early the following year, unless an exceptionally dry summer is evident, when special care must be taken to see that sheep do not concentrate entirely on creek banks and river beds, which

become hotbeds of infection and typical danger areas. (4) Hand feeding or winter feeding must be started early, because 1 1 sheep become too weak loss of appetite results, with subsequent mortality. (5) It is important with rotation of sheep and cattle that the latter should be over 12 months, when they do not harbour parasites which may be a dangerous menace to sheep. Treatment of Calves Throughout, sheep have kept well in the foreground, but the principles of prevention apply equally well to calves. Unfortunately, knowledge about calf parasites is rare, but there is little question that heavy losses do occur from this cause. Where calf paddocks are used the year round without spelling, and where no rotation of calves is practised, heavy losses must inevitably occur in the favourable season. The following drenches can be used with some effect, varying in efficiency with the parasites present:— (1) Bluestone—Dissolve Boz bluestone in three gallons of water. Dosage: Calves, four months, 3oz; six months, 4oz; nine months, 6oz; 12 months, Boz. (2) Carbon Tetrachloride. This m jv*i.-o froruionfly need for calves In high dosage, but when a lime deucilu~,v i B cv.ceu heavy losses may occur from poisoning. (3) Tetrachlorethylene.—This can be used in doses of from 10 c.c. to 30 r r in Unuid paraffin, but should be followed by a dose of Epsom salts.

Dosage 2 p.c. 4 p.c. 5 p.c. oz. oz. c.c. c.c. Adults .. , 2 1 (30) 20 Two-tooths 1J i (25) 15 Lambs — 8-12 months . 1 i (15) 10 4-8 months . i * (10) 8 Under 4 mths. | i (8) 5

Dosage 2 p.c. 4 p.c. 8 p.c. oz. OZ. c.c. c.c. Grown sheep . 2 1 (30) 20 Two-tooths li i (25) 15 Lambs— 4-12 months . i (10-15) 5-10 Under 4 mths. J i (8) 5