"Sleepy Sickness" and Bearing Trouble in Ewes

New Zealand Journal of Agriculture, Volume 71, Issue 1, 16 July 1945, Page 37

"Sleepy Sickness" and Bearing Trouble in Ewes

Prevention by Suitable Methods of Management

By

A. D. G M. LAING,

M.R.C.V.S., V eterinarian, Hastings.

“OLEEPY sickness” (ante-partum paralysis) and bearing trouble O together account for a very large proportion of the mortality and indirect loss in ewes at lambing time. In certain districts, for instance, the average incidence of bearing trouble may amount to 4 per cent., about half the ewes affected either succumbing or having dead lambs. As both these troubles are due to causes connected with nutrition, it will be profitable to consider certain aspects of the treatment of pregnant ewes.

THE essential factor to be borne 1 in mind, in the management of in-lamb ewes is that just . as milking cows require so much feed for the maintenance of their bodily requirements and so much more for milk production, so does the pregnant ewe require so much to keep herself and so much more to develop the one, two, or even three lambs she is carrying. The important point, however, is that in-lamb ewes do not require nourishment in an evenly-in-creasing ratio. Their needs are comparatively small during the earlier part of pregnancy and disproportionately heavy towards the end. Investigations have proved that most of the foetal growth takes place during the last third of the period of pregnancy. In the case of the ewe it may in fact be stated that during the last five weeks of pregnancy she is called upon to provide half the total growth requirements of the lamb or lambs she is carrying. It is obvious, therefore, that special care should be taken to provide nourishing; feed during the month prior to lambing. ANTE-PARTUM PARALYSIS. The more correct name for antepartum paralysis, or sleepy sickness, is pregnancy toxaemia (toxaemia meaning poisoning). It is also sometimes known as twin . lamb disease, from the fact that in 95 per cent, of cases the ewe is found to be carrying two or more lambs. Its incidence is world-wide, and in New Zealand the losses in most seasons are appreciable, and in some years serious. It appears to. be associated with a feed shortage occurring during the latter part of pregnancy. Heavy frosts and dry spells in spring, factors which result in a feed shortage at this period,

should both be looked on as predisposing causes, and precautions taken accordingly by those who have the handling of the ewe flock.

In order to give a clear picture it is necessary to give a very sketchy description of the extremely complicated process by which the sheep converts pasture into flesh and blood, etc. A balanced proportion of the three main food factors, proteins, fats, and carbohydrates, is required. These are all broken down by the digestive juices and action of the liver into simple substances, waste products being excreted.

These simple substances are carried by the blood fluid to the muscles and there “burnt up” with the oxygen absorbed from the lungs, the resulting heat being the energy by which the body lives. A number of minerals, phosphorus, calcium, iodine, etc., are also essential to life and to the satisfactory working of the processes outlined above. It must be emphasised

that the liver plays a very essential part.

When food intake is in excess of bodily requirements the surplus is stored as fat. If the daily food is in-

sufficient, then the fat reserves are called into use. The liver is the organ by ' means of which the body reserves of fat are converted into the simpler substances, in which forms alone they can be made use of to support life. In the pregnant ewe the position is further complicated by the heavy requirements of the foetus during the last month of pregnancy, and

the several factors result in inefficient functioning of the liver, the formation of injurious substances in it, and the setting up of a condition of toxaemia or poisoning. Ante-partum paralysis has on a number of occasions been caused experimentally in pregnant ewes, and blood and other tests have confirmed the above conclusions. Symptoms The symptoms occur at 10 to 20 days before lambing is due. The ewe is dull, off feed, and keeps separate from the flock. The earliest noticeable sign is frequently a loss of control over the limbs. When driven, the ewe will trip up or cross her forelegs. Later, she , will stand stupidly and be moved only with difficulty. The eyes appear glazed and sightless. She may stagger or walk in circles. As the condition gets worse the ewe lies down, and if raised to her feet, collapses again after walking a few paces. She may live for several days in this condition, death occurring in a few days from when the earliest symptoms appeared. Appearance of Organs The general condition of the organs after death is good. The lamb or lambs in the womb appear quite healthy. The liver, however, is quite abnormal, being enlarged, pale, yellow, very easily broken, and greasy. Some of the internal fat may have a patchy, parboiled appearance. Treatment Nothing can be done once the case is far advanced, because the liver has

become completely useless. In the early stages, however, while there is a desire for food and the ewe can move about, dosing with Jib. of molasses or syrup, repeating daily, gives a good chance of a cure. In the case of valuable stud ewes the expense of 1 treatment by a veterinary surgeon with insulin and glucose may be justified, and good will usually result. If the ewe lambs, the symptoms will disappear. The important point, however, is that the affected ewe should be able to graze, and as long as that is . the case treatment on the above lines has a good chance of being successful. It is essential that ewes under treatment be put on succulent feed, such as young grass or green barley. Care of Affected Flock Every effort should be made to supplement the feed of a flock in which cases of sleepy sickness occur or are suspected. Good-quality hay, preferably legume, and succulent greenfeed, such as young grass or barley, should be made available if possible. In cases in which the flock is in high condition daily exercise appears to be of considerable value, both in itself and because the presence of affected ewes may be disclosed by their tripping up when driven, so that they may be picked out in the earliest stages for special treatment. A good plan is to muster the affected mob daily and drive them slowly for half a mile to a mile to good pasture and back again after one or two hours, but the exercise must never be carried to the extent of interfering with nourishment, as that will bring on the condition it is desired to prevent. Prevention No deficiency of calcium or other mineral has been diagnosed in sleepy sickness. A calcium deficiency does occur in lambing sickness, which is a different disease, and one which occurs much more rarely than sleepy sickness. Lambing sickness, being a form of milk-fever, yields readily to calcium gluconate injections, but in the much more common sleepy sickness such injections are of no value. Prevention, therefore, is best sought by common-sense and general care of the flock. 1. Ewes should be in good condition, but not fat, at tupping time. 2. If any shortage of feed is anticipated, it is better that it should occur, as far as is practicable, during the earlier rather than the latter part of pregnancy (note the disproportionate foetal requirements during the last month). The old idea of allowing the ewe to “live on her own fat” during the latter part of the winter is indeed one of the principal factors in bringing on sleepy sickness.

3. The ideal is that ewes should rise slowly in condition from tupping - to lambing, farm management being directed to that end. Such a policy will ensure a minimum of casualties and a maximum milk supply for the lamb. 4. Where paddocks are not topdressed a lick composed of equal parts of . bone meal or bone flour and salt should be made available.

5. To enable the above policy to be carried out it is essential that reserves of winter feed be carried from year to year to offset uneven pasture growth in certain years and seasons. 6. If it appears that winter feed may be insufficient, it is far safer to keep the ewe flock short during the earlier part of the winter and do them well during the latter half and in early spring, than the other way about. BEARING TROUBLE IN EWES. ■ The more correct name for bearing trouble in ewes is eversion of the vagina. The term “red bag” is frequently used, arising from the appearance of the everted membrane. The condition can occur in any of the domestic animals, and does do so to a rare extent everywhere, both shortly before and shortly after parturition. The epidemic form some days before lambing occurs in New Zealand in seasons which favour its development. The trouble appears to have come to notice fairly early in the history of New Zealand farming, but it was only about 1890 and in. the early years of this century that it became widespread. While a small

proportion of cases occur in dry ewes in poor condition, in the great majority the ewe is pregnant and in good order. Symptoms Symptoms occur about seven days, although often longer, before the ewe is due to lamb. The protrusion of the membrane lining the vaginal pas-

sage from the vaginal orifice in the form of a large, reddish swelling is the first sign. The ewe is listless and uneasy, grazes little, and tends to separate herself from the flock. The swelling increases with time, both from straining on the part of the ewe and from the accumulation of blood in the extruded part. If it is not treated, inflammation sets in, the ewe cannot make water, and death ensues. Occasionally the “bearing” will return of its own accord, especially in those cases occurring in dry ewes. The vast majority of affected ewes are 4-tooths and 6-tooths and upwards, and it is rare in 2-tooth ewes. Organs After Death There is usually much abdominal fat present in the organs after death. The liver ( is pale and greasy. In 90 per cent, of cases twin lambs are being carried. The bladder is enormously distended with urine. Cause f " This condition is due to incorrect nutrition. The immediate chain of circumstances is:— 1. The ewe has been carrying too much condition, and the muscles are soft and lack “tone.”

2. The flock is rarely disturbed and feed is plentiful, but inclined to be rank. 3. The ewe lies down to ruminate for long periods, during which the bladder fills up. - 4. She gets up to urinate only when the bladder is full. It may be noted how invariably such sheep, when disturbed, immediately make water. 5. In all animals, when the bladder is excessively full, a nervous contraction of the neck will take place, preventing the act of urination for a few seconds. 6. The. ewe then strains to bring about urination. Straining consists of a contraction of the muscles lining the abdomen, etc. 7. This contraction forces the organs backwards into the pelvis. 8. The paunch is full, feed being plentiful, and the womb is gravid, usually containing two foeti. Much abdominal fat is present. All these factors increase the pressure mentioned below. 9.. The neck of the bladder is pressed against the aitch bone by the abdominal organs coming backwards from the straining.

10. Should the ewe attempt to make water when lying down, the tendency to close the bladder is still greater., 11. The ewe is now in a “vicious circle”: the more she strains to urinate the more effectively is the neck of the bladder closed, and the longer the bladder, is closed the greater is the straining to make water. 12. Eventually the vaginal lining is , forced out to the exterior, which is the condition of “bearing” out. Treatment If the ewe can be treated before the extruded membrane has become congested,- injured, or filthy, a good percentage of cures can be obtained. •' The not uncommon cases of relapse after lambing should be watched for and treated on the same lines. The part should be gently cleansed. Condy’s crystals at a half-teaspoonful to a gallon of water, freshly prepared daily, is recommended, or any of the well-known coal-tar antiseptic preparations at suitable dilution. Strong or irritant antiseptics must be avoided, as they cause, straining. For the operation of replacing the membrane the operator’s hand and forearm must be clean and the nails short and even, and they should be smeared with carbolised oil. The

vaginal membrane can then be returned into place, keeping it in position with the hand until it is warm and the blood has begun to circulate.

Administration by the mouth of one ' drachm of chloral hydrate (this can most easily be given in a small-size gelatine capsule) will help to prevent the ewe straining and forcing the bearing out again. One ounce of a weak . solution (2 per cent.) of bluestone should be given with the capsule to ensure its passing straight into the fourth or true stomach. Raising the hindquarters will also materially assist. When the operation is completed two or three locks of wool should be tied across the vulva to help to retain the membrane in place. Stitching, safety pins, , and other materials to pin the lips of the vagina together are best reserved for chronic cases of relapse of the trouble. A piece of an old tyre inner tube 4in. square with a small hole for the escape of urine and tied by binder twine to the wool on the flanks is also helpful. An old method, crude but effective, in the early stages was to secure the ewe to a wire fence for a few hours, so that the hindquarters were well off the ground, care being taken that there was no risk of suffocation from pressure of the paunch on the chest. The womb slips forward, the ewe makes water, and when the animal is liberated the bearing remains in. On no account should materials such as bran or short wooden sticks be placed in the vagina to retain the bearing mechanically. Such remedies may seriously injure the ewe and are, in any case, of little value. Prevention Outbreaks of this trouble occur after a mild winter, when food has been plentiful and the pastures rank in growth, and when the ewe flock as a whole has been in too high condition. For example, in 1908 and again in 1938 in Hawke’s Bay the rainfall s from January onwards was far in excess of the average and the seasons very mild, with resulting tremendous growth of pasture. In both these years the incidence of “bearings” was very much higher than usual, while those seasons in between in which there has been a high incidence of bearings have shown similar climatic and general conditions on a somewhat milder scale. Prevention is on common lines, that is, as mentioned earlier in this article—ewes to be in good condition, but not fat at tupping time, and to have sufficient feed to keep them rising slowly in condition throughout pregnancy, allowance be-

ing made for the disproportionately large requirements of the foetus during the last month. Where feed is plentiful and the ewe flock appears lazy, if the ewes are mustered quietly once daily , and given a change of pasture and gentle exercise for one to two hours, the trouble will be largely prevented. The object of the exercise, of course, is to keep the muscles, as well as the general system of the ewe, in good “tone.” General ' > The following is a quotation from a standard text-book in regard to this condition, (eversion of the vagina) in the cow: — “This accident may occur in wellshaped cows whose tissues, and especially, those of the genital organs, are soft and relaxed — of a lymphatic temperament, with a wide pelvis, and which are fed on an abun-

dance of bulky but not nutritious food.” ' It is certainly the short, blocky ewe with the wide pelvis which is the most liable to put out her bearing, and the parallel case in the cow is of considerable interest. In the cow it is rare also at first calving. Summary 1. Ante-partum paralysis and “bearings” between them cause much the greater part of the annual ewe , mortality. ;. ' 2. The causes of both are nutritional and they are preventable by suit- * y able methods of management. 3. To overcome climatic variations reserves of supplementary feed, hay, ensilage, etc., should always be available. The two first-named can, of course, last for years until required and need not be touched in good seasons.