AFRICAN HORSE-SICKNESS.

New Zealand Herald, Volume XXXVI, Issue 11200, 21 October 1899, Page 5 (Supplement)

AFRICAN HORSE-SICKNESS.

WHAT MAY HAPPEN TO OUR

HORSES IN THE TRANSVAAL. j South Africa is remarkable for the extra-1 ordinary fatal epidemics of various diseases I which sweep off the animals most useful ! to man. In recent years we have heard , that the oxen which do so much of the j transport work in the interior of the coun-' try, and whose herds constitute the wealth of the farmers, have been ravaged by a visitation of rinderpest, causing widespread ruin and paralysis of trade. But worse almost than rinderpest among cattle is the horse sickness or " Paard Zickte" which is a yearly visitor in most districts, sometimes taking a specially virulent form. All officers who have served in our recent campaigns in South Africa or have been garrisoned in any of the country's military stations, must have had more or less experience of it, and know well how much it is to be dreaded lest it should peremptorily destroy the efficiency of an army's mounted troops and render any force immovable by the wrecking of all transport. The horse-sickness is no new curse that has smitten the land, but it has been a familiar evil since the first European settlement. It appears, however, that during the early half of the century it only came in a virulent epidemic form at long intervals of time, and lay partially dormant for the intermediate periods. 1856 and 1857 were particularly disastrous years, aud it is recorded that then more than 64,000 animals died in Capo Colony alone, causing severe agricultural depression in the eastern and western districts. As an example of what may happen, I may mention that two years ago, in Natal alone, 600 Government animals, horses and mules, died", and this in time of peace when there was no unusual exposure or trial. But it is in the midst of field operations that an outbreak of horse-sickness is most disconcerting, and I may enlarge a little on the staggering nature of the blow to a commanding officer of mounted troops when such an outbreak takes place in the lines of his corps. In the presence of horse-sick-ness, he finds himself utterly helpless. The pestilence strikes suddenly, rapidly, and irretrievably. Its arrival cannot be foreseen, for though its cause is known the action is still to a great extent wrapped in mystery, and though precautions may be taken in peace time that have a preventive value, they cannot be carried out in any effective manner during a campaign when it is necessary to act with other troops or to vigorously complete a strategical operation. Our commanding officer has had a hard day's work in the saddle and possibly has done a little fighting. He carefully inspects all his horses as they stand picketed in the evening in the camp or bhouac, and his spirits rise within him when he sees that they look bright and well, and are munching their feeds with a good appetite. He thinks with satisfaction that all are fairly sound and fit for the morrow's work Whatever it may be, and that the men whom he has trained so carefully will be well carried and able to show their intelligence and gallantry. But, when the morrow comes, perhaps the first report he receives is that four or five horses have been found lying dead in the lines. There has been no disturbance during the night, and the sentries have noticed nothing unusual. The poor brutes have simply lain down and have been overtaken by a swift' death.

Besides those that are dead there are several m'ore that are reported as "looking rather queer.'' And indeed so they are, some glancing with uneasy eyes at their heaving flanks, as if suffering from internal pains, and some with hanging heads and a profuse discharge pouring from their nostrils. These sick ones, of course, cannot be saddled for the morning's parade, and, though they will have immediate treatment, it may be feared that the hand of the destroyer is upon them. At one fell stroke perhaps eight or ten of the best horses (and .they that are taken are generally the best) are cut off from the available strength of the corps. All the other horses, however, eat their morning's meal with apparent zest, and it is hoped that the worst is known. The parade is formed and the corps moves off for its day's duty, but before they have gone half a mile one of the trooper's- horses gives a suspicious cough which strikes the commander's ear. He hopes that the cough may mean nothing, but he has misgivings, ar.d sends the horse back. He has lost the services of another man, a very serious matter, indeed, if there is any chance of a skirmish, but he has to get through the day as best he can. When he is once more in his bivouac he finds that all the horses are dead which he left sick in the morning, and the horse with the suspicious cough barely lived till midday. And so on, and so on. Night by night and day by day horses fall sick and die, or, if by chance a few recover, they are so shattered and pulled down that they are quite unfit for work until they have had a long rest and sedulous nursing.

It is not proposed here to attempt to describe scientifically the symptoms of horsesickness, but though unquestionably the disense is the same, there are, roughly speaking, two distinct manifestations of it, one when it attacks the pulmonary organs and one when the stomach and digestive organs are specially affected. The only difference in the result between these two forms is that death is generally much more rapid in the first case than in the last. When the pulmonary organs are the seat of the disease the first indications are a dull cough or laboured breathing followed immediately by other well-known signs of high fever and extreme illness. Occasionally the horse's head swells enormously, and from this the Dutchmen give the name "Dikkop" (big head) to the complaint. There is a discharge from the nostrils the animal rapidly sinks to the ground and lies on its side, and in its last moments the nose discharge turns to a froth as white as snow, which forms a cloud in which the victim is half concealed before death comes as a relief from its agony. In this, case a post-mortem examination shows the respiratory organs to be gravely affected while the digestive organs are comparatively healthy. When the reverse is the case and the digestive organs are attacked, in most cases the signs of disease do not succeed each other with such startling rapidity, but the horse first shows unusual dulness and Lethargy, refuses his food, and shows that he is suffering from internal pains by pawing the ground, looking restfully at his flanks, then lying down and rolling in his uneasiness. Slower though the progress of this form of the malady may generally be, it, too, is sometimes almost instantaneous in operation, and may cause death in a very few hours. In epidemics of horse-sickness it is remarkable that the virulence of the poison that affects the animals never seems to decrease. At the end of an outbreak or at the end of the sickly season the severest cases may occur, and at any time there may be cases in which the symptoms are not so exaggerated, and in which treatment and nursing may be effective and the animals may recover.

Apropos of recovering there is a general belief in South Africa that horses which have recovered from horse-sickness are thenceforth supposed to be safe in a succeeding epidemic. They are locally said to be " salted," and, being so, they have a very special value. In fact, other qualities being equal, a "salted" horse will fetch nearly double the price that would be paid for one which has not gone through an attack of the disease. It is conceivable that a horse, which has sufficient strength of constitution to throw off an attack of horse-sickness, may not be so liable to the disease as others, but the belief that the passing through one attack gives any immunity from a second is quite fallacious. It is certain that, in a local mounted corps employed in the Transvaal, several horses which had suffered and recovered from well-marked attacks of horsesickness in 1877 were among the first to die during an epidemic in 1878. ■ How is horse-sickness generated? What are the causes that lead up to such fatal issues? In order to explain the most commonly received theories on the subject a word must be said on the general method of feeding horses in South Africa. Oats are very little known, and hay is seldom made and is expensive and difficult to procure. In place of the former, horses receive rations of what are locally called mealies," that is the dried grain of Indian com, and, in order, to supply the more bulky form of nutrition, they are turned out to graze on the veldt. To prevent them from straying while grazing the head of each horse is fastened by a raw-hide strap to the upper part of its leg just above the knee in a fashion called kneehaltering. 'This permits a horse to move comparatively' slowly without • discomfort,

but prevents him from galloping and being quite independent. Two or three mounted nkn can easily watch a mob of two or three hundred horses thus hobbled, and if any of them show a disposition to wander can with small exertion overtake them and drive them back to their comrades. Good South Africa grass is very nourishing, and horses thrive and grow fat upon their mealies and their grazing in a most satisfactory manner. The mere facts of being necessarily in the open and picking up their own food are an approach to natural conditions which has many advantages. , To revert to horse-sickness. Like most epidemic diseases, it is believed to bo duo to the action of a specific bacillus, which enters the animal's system by the air which it breathes or by the food which is eaten. This bacillus comes from the soil, and especially from foul, swampy, or marshy ground". The vegetation on such ground is laden with it, and it floats in the watery vapour that rises with evaporation. It may thence be caught up and wafted on currents of air, but it is then no longer in overpowering numbers, and its influence may sometimes, though not necessarily always. be so far diminished. The Dutch farmers of the Cape have long had a practical, if no« scientific, knowledge of the conditions most favourable to horse - sickness, and they have kid down the rule that horses which are turned out to graze should not be allowed, at certain seasons of the year, to feed along river banks or near the swamp hollows known as " Vleys," neither should they Dfl turned out before the sun is well up and has scattered the miasmatic vapours, or allowed to be on low-lying ground after sundown when the evening mists aro rising. And, unless extreme vigilance is practised, it is difficult to keep horses away from the neighbourhood of watercourses, for naturally in such places the grass is peculiarly rich, fresh, green, andi tempting; if they are left to themselves, they will almost certainly seek the most unhealthy spots, and expose themselves to the germs of a deadly malaay. The Boers, too, were well acquainted with the fact that the horse-sickness clings especially to low-lying plains, and they have always been in the habit of moving their ground. Even an elevation of' 300 ft was considered to give comparative safety, and in certain districts that formed elevated plateaux cases of horse-sickness were very rarely known to occur. The horse-sickness generally appears in greatest severity towards the middle or end of autumn, which is also the rainy season. The semi-tropical showers loosen and Soften the soil, and the emanations that then arise carry the poison with them into the grass and the air, giving it free scope for action. With the approach of the cold weather in May the disease disappears, or at least there is no general epidemic, though occasionally sporadic cases have been known to exist in winter. The belief that there is no horse-sickness after the first frost is, roughly speaking, correct. 11l this connection it may be remarked that for the last 30 years there has been comparative freedom from horse-sickness in Cape Colony. This period is coincident with the large introduction if sheep, whose flocks have eaten down and destroyed the small shrub called the karoo bush that at a former time sheltered the rank grass, After all, the most important point, at which we now wish to arrive is the method for doing battle with a disease confessedly rife over a vast extent of country, and deadly in the highest degree. When the poison has once been received into any animal in a vigorous form, there seems to be no doubt tuat no known treatment m&y be reckoned upon to effect a cure. The only question that remains is, what sre tlio preventive measures which may be adopted either to ward off an epidemic or to modify its effects? Nothing in the nature of inoculation has been discovered, and, 'ndeed, as we have seen that horses that nave undoubtedly suffered from the disease are still liable to its subsequent fatal action, so it would seem to be time wasted to create a mild attack with the view of staying off a more serious one. The only thing that seems to be in our power is to guard or? horses from the miasmatic air, and tM food which is laden with the deadly bacillus. Nobody has more thoroughly and closely grappled with the question than Veterinary-Colonel Lambert, C.8., late Di-rector-General of the Army Veterinary Department, in a most valuable pamphlet written in 1881, giving the fruits of his large experience as P.V.S. in Natal, and anything that may here be said is gathered almost entirely from his observations.

We should " take steps to place our horses and mules during the sickly season as much as possible out of reach of the soil-developed poison, especially during the night and early morning, for these are the most dangerous times, when the foul poison germ-charged mists and dews are concentrated, and sire not dispersed by the life-giving sun. When we can do this, as we often can, without interfering with the animals' daily work, it is an act of folly not to do so. . . . If we have any number of animals, and some begin to bo attacked by horse-sickness, we ought at once to remove tho rest to fresh ground, and it should be, if possible, high and healthy ground, the higher the better, for these soil-developed poisons appear only to be able to rise to a certain distance from where they are usually produced. . . . It must not be thought that the removal is a failure because a case occurs during the first day 01 two afterwards, because it may have been contracted on the old ground. But, if cases continue after the first two or three days, another move should be made. . . . We saw last season hero a most destructive attack of horse-sickness cut short by moving the amen Is less than three-quar-ters of a mile to very much higher ground, whence tliPv did their ordinary work, Where it is inconvenient or impracticable to change the situation of animals, as those working in towns, they should be fed during the sickly season on dry fowls—oat forage, mealies, bran, etc.—and no wet or freshly-cut grass, or better still, no grass at all should be given."

There is a very common belief that horses which are stabled are not so liable to horsesickness as others, and there can be no doubt that the better cared for an animal may he, the more ho is protected from draughts, and the more attention that is paid to the quality of the food, the less likelihood is there that he will be ptruck by disease. But stables that are "located on or surrounded by foul, swampy, or marshy ground, or close to running streams," can give no possible security. Special preventive horse equipment has had a trial, but its employment does not appear to have had any measure of success. "During the Zulu war, we had in the 17th Lancers, on our arrival in this country, nosebags of flannel issued to filter the air at night, and to prevent the horses from eating tho dewy grass, but we did not find those which wore them lees liable to the sickness than those without them. This is not to be wondered at, for such contrivances are constantly getting out of order, and, besides, are obviously, when we consider how the disease is produced, imperfect and inadequate for the purpose intended. It is not, however, denied that in some bad situations they might bo useful."

Something has now been said about the knowledge of horse - sick-ieas that we possess, how it originates, how it acts, and how it may in some degree be combated, It will be seen that, so far, science has not progressed beyond making some suggestions as to avoiding its ravages, and it will be easily understood how difficult it would be to carry out with the horses of cavalry and artillery and the mules belonging to the transport with hay and other dry foods and all must of necessity be turned out to graze sometimes. _ With the exercise of great care and strict surveillance they may be prevented from feeding near watercouses and vleys, though, where numbers are concerned, this will be very difficult. High ground may be sought for the establishments of camps and bivouacs, but in doing' this much must depend on the movements of the enemy and the other conditions of a campaign, and when an outbreak of disease takes place, it may be quite impossible to move the military animals even a short distance for the sake of changing the lines where they are picketed. The only absolute resource that is left is that no cam- • ' ■' paign in South Africa should be undertaken i in the sickly season, and that all great movements of troops should be restricted ' to the winter and spring. It is a source 0/ > satisfaction to know .at least that the dangers of horse - sickness are perfectly well recognised, and that every difficulty and embarrassment that can arise may be foreseen • and provided for if they cannot be avoided. ' It is obvious also that the horses of a • possible enemy will be exposed to the same danger as our own, though, as they aro native to the soil, and are therefore acclimatised, it may be in a somewhat smaller degree.—Daily's Magazine, j' „M 1 • I - ~r , ' AVsiIV.V.'!