Observations on Glanders and Mallein

Observations on Glanders and Mallein

CI 1;\llCAL ARTICLES. 3-+3 eLI N I CAL ART I C L E S. --0-- OBSERVATIONS ON GLANDERS AND MALLEIN. By OBSEKVElZ. 1 AMONG horse-owners and the gen...

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CI 1;\llCAL ARTICLES.

3-+3

eLI N I CAL ART I C L E S. --0--

OBSERVATIONS ON GLANDERS AND MALLEIN.

By

OBSEKVElZ. 1

AMONG horse-owners and the general public different opinions exist as to the causes which lead to the prevalence of glanders. Some have put the blame upon the stables in which the horses are kept, and this idea has caused many stables to be renovated and altered or even pulled down. It is also supposed that horses imbibe glanders with the water which they drink, and at one time belief in this cause gained such prominence that for a short period public drinking troughs were closed. The complaint being most frequently seen in animals that are in poor condition and badly cared for, it was only a natural conclusion to consider that bad food, overwork, and other debilitating influences had much to do with the production of the disease, and vice versa, that good food, g'ood sanitary arrangements, etc., prevented it. The influence which these views have had upon the general health and comfort of horses has been beneficial, but unfortunately they have done little to exterminate glanders. At all events this had been the experience of the managers of the stud in question. The stables, which were of necessity in different localities, although consisting of every variety of building were all arranged to allow In no case was the sufficient air space, ventilation, and drainage. air space less than 1400 cubic feet per horse, and many had more than that amount. There were besides ample facilities for thorough ventilation. Surface drainage was adopted; the drains were all outside the building and bad smells were unknown. The diet was liberal, and every care was taken to prevent overwork. Regular inspections were made, and all animals that appeared in poor condition were either put to lighter work, or treated, as the case might require. In short, everything was done to maintain the stud in a high state of health and efficiency, yet with all this care and supervision cases of farcy and glanders occasionally occurred, the average annual loss from this cause being rather less than 1 per cent. Of course, when a case was discovered all the regulations laid down by Local Authorities were rigidly carried out; stalls were cleansed and disinfected, harness, clothing, etc., destroyed, and all horses which had been exposed to the risk of infection were for a long time isolated, or, when they were of little market value, destroyed. It was in consequence of one of these outbreaks that the managementwere induced totrymallein. I twas at first only used in a few stables, where the diseased animals had been located, but owing to subsequent events the whole of the stud was tested in this way. The gross result 1 Glandels has for :\ long time figured ,"\8 sneh a In,ltln,nme anlI dangerous diseaRe that fe,,,, if any le~pectd.ble hOl'se-OWnel'K care to have the1r names a~~oclc-l.t~d \Hth It. In deference to thm feeling, the locality and the n,\llleS vf the propl'ietOls who have c,l.u.':led ::t l::ugtl nnmbel of expellment~ to be nmde In their ::.tlHl with mallein are wlthheld, and for the same reason the Wl'lter of the altlCle h<1'& pleferre(l to use a ;WII~ deplwnt. The facts, huwevel, rue as lehabk as if they "ele duly sIgned and vouched for by &Ollle well-known Individual. Z

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of this experiment was that about 8 per cent. of the stud ga\'c the typical reaction, although the reacting animals otherwise appeared in perfect health. This result naturally caused some consternation among those responsible. Doubts were expressed as to the correctness of the test, and all the horses which had reacted were again injected. The result of the second testing was in the main confirmatory of the first, and the question as to what was the best thing to do with them had then to be decided. Some said they should all be destroyed, giving for their reason that the law said so, and also that they were dangerous to other horses and to human life. But it was pointed out that the main risk to individuals looking after glandered horses arises from their liability to contract the disease by any sores which they may have becoming infected with discharge from the nostrils or from ulcers on the legs, etc., and that as none of the animals had any discharge there could not possibly be any serious danger to their attendanb. Danger to other horses could be obviated by keeping them in separate stables; and, with respect to the legal aspect of the case, it was pointed out that the law in this country had not yet recogn ised mallein as a test for glanders, and that to separate and work these horses under certain conditions was a perfectly legal course, since a high authority had stated this to be the interpretation which the Board of Agriculture placed upon its own order. It was further pointed out that, so far from any of the animals showing any of the clinical signs of the disease, they appeared in the bloom of health and condition. In fact, in many cases there had been a marked improvement in their appearance since they had been tested. It was finally decided, after full deliberation, to keep the horses that had reacted by themselves and await developments. vVhell any of them became useless they were to be destroyed instead of sold. Perhaps a few remarks explaining the method adopted for injecting the animals may not be out of place here. The horses being in regular work, the time selected was Saturday evening, about an hour after their last feed; their temperatures were then taken, and if it did not exceed 102 F. they were injected with 20 m. of mallein. The place selected was about the centre of the neck, sometimes the ncar side, sometimes the off. Beyond a thorough disinfection of the needle and syringe after each injection no precautions were taken. The temperatures were taken again at the tenth, thirteenth, and sixteenth hours afterwards, and any alteration in appearance, such as staring coat, loss of appetite, etc., was noted. The size and character of the swelling, if any, at the point of inoculation were noted at the thirteenth and thirty-sixth hours, and in some cases the temperature was taken again at the twenty-fourth and thirtysixth hour. This plan has been found to be sufficient for testing horses apparently healthy and in regular work. Where horses were suffering from any ailment the temperature was taken several days before injection. . An animal was considered to have given a typical reaction when its temperature rose to 104 or more, attaining its highest about the thirteenth hour, and then gradually declining until by the thirty-sixth hour it was normal. v'lith this rise of temperature there was nearly always 0

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some constitutional disturbance-shivering, staring coat, and a dull miserable look. The swelling at the seat of inoculation was at the thirteenth hour about 3 or 4 inches in diameter, and it was as large or larger at the thirty-sixth hour after inoculation. It was painful, and inflamed lymphatics could be seen running from it. The neck was stiff, and the animal seemed afraid to move the fore limb on the side of inoculation. The infiltration was slowly absorbed and gravitated down towards the chest. This combination of symptoms was considered a typical reaction , and it may be accepted as quite as diagnostic of glanders as the characteristic ulcer on the Schneiderean membrane, the enlarged submaxillary glands, or the peculiar sticky odourless discharge from the nostrils. The post-mortem appearances have always confirmed the opinion that the animal so reacting is glandered. It must be admitted, however, that anyone but an expert is apt to be disappointed at the post-mortem examination. From the great local swelling and constitutional disturbance very extensive disease of the lun gs is apt to be expected, but very often the whole of the morbid lesions consist of two or three tubercles about the size of a grain of rice in the lungs. They may be grouped together at the border of one lung or scattered singly over the surfaces of both, and occasionally it requires a good deal of searching to find them. The microscope, if nothing else, proves their true nature, and shows the delicacy and accuracy of the mallein test. Writing now after more than twelve months experience of the arrangement described aboye, it can only be stated that the results have been unexpectedly satisfactory. Not one of the isolated horses has developed any of the clinical symptoms of glanders although doing full work. This result was not quite anticipated, but it was highly satisfactory to all concerned. Although the previous losses from g la nders had been small, to be free from the disease for one year (w ith only one exception, which will be noticed below) was worth all the expense and trouble which the testing of the stud had cost. The conclusions to be drawn from this experience are important, although perhaps they cannot yet be accepted as final. It would almost appear that mallein, besides its diagnostic properties, has also the p ower of arresting or retarding the development of glanders. It must , of course, be admitted that we are in the dark as to the length of time it would have taken for any of these isolated horses to develop clinical symptoms, but, judging from the average cases during the ten previous y ears-that is, assuming that mallein had not been used, and the same animals had continued in the stud-oneeighth of them, or about I per cent. of the whole stud, would have been destroyed for farcy or glanders. Are horses which have reacted to mallein but otherwise appear healthy a source of danger? In other word s do they communicate the disease to the healthy animals with which they come in contact? The reply which the experience in this stud up to the present dictates to this query is that they do not readily communicate the disease. An examination of the hi story of the reacting animals at the time they were injected showed that in them the malady was in a very latent form. Numerous cases occurred where animals had been for a long time working together as a pair, and yet only one of them gave

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the reaction; in uther cases, where they had been standinf; in the same stalls without any separation at their heads, one horse would give a reaction, but neither of the animals which had been standing alongside of him for months would give any reactioll. The fact that horses which more than two years ago gave the typical reaction have not yet developed any of the clinical symptoms of glanders, has an important bearing upon this question. Through an oversight a horse which had reacted (rise of 2'8 F., and ten days afterwards 1'2 F.) was sent to work with healthy animals. At the expiration of nine months it died after a short illness, unconnected with glanders, and at the post-1Ilortem glanders tubercles were found in the lungs. The horses with which this animal had been working were immediately retested with mallein, but it produced not the slightest effect on either of them. However, the following case, which occurred quite recently, had a different ending. A. pair of fat healthy-looking horses gave the typical reaction twice (they were stabled in bales), but a horse which had stood next to them for two years gave no reaction. Owing to their having some vicious tricks in the stable, difficulty arose in the way of isolating the two reacting horses, and in view of the length of time which the healthy horse had been standing alongside of them it was decided to let him remain. Matters went on well for eleven months, when the horse which had not reacted to mallein was found to be ill-feverish, sore throat, and swelling of the hind legs-and in the course of a week a farcy ulcer broke out upon one limb. The animal was destroyed, and the lungs were found to be glandered. His stall remains vacant, although the other horses still appear quite healthy. From this case it would seem that horses which haye reacted to mallein are occasionally a source of danger to healthy animals, but the preponderance of evidence is in favour of the conclusion that as a rule they may be considered harmless. These cases, however, raise a difficulty for the solution of which time and carefully-conducted experiments will be required. 0

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A CASE OF VOMITION IN A HORSE, AND ITS CAUSE.

By E. M. JARVIS, M.R.CV.S., Kensington. I WAS called to see an aged bay carriage gelding on the 25th February last. There was no previous history, and I found him turned loose in a box, and, as the owners were out of town, feeding on bran mashes and hay. I was told that he had been vomiting for about an hour-anda-half, and had only ceased a little before I got there. The food had been ejected from both nostrils and the mouth; he behaved "like a person who was sea-sick," and made a noise something between a low squeal and a squeak. I noticed on entering the box that some blood was scattered on the walls, together with fragments of masticated food which the animal had evidently ejected there as a dry frothy discharge; pieces of chewed food were also sticking to the interior of his nostrils, and some more of the same material was strewed