THE VETERINARIAN.

New Zealand Mail, Issue 810, 9 September 1887, Page 14

THE VETERINARIAN.

Black Leg or Quarter 111. ‘The Field.’ Recently we referred to the experiments which have been made at the royal Veterinary College, under the auspices of the. Royal Agricultural Society, with the view of arriving at a method of protective inoculation for black leg. A provisional conclusion—or rather inference—has been arrived at, which further experiments may, or may not, confirm. Meanwhile it will be interesting to inquire what is the nature of the disease against which it is proposed to protect susceptible auimals. Stockowners are well aware that black leg is a disease which is almost peculiar to young cattle. It is not necessary to discuss the question of the age limit of the disease, nor is it of much consequence that cases of the disease among adult cattle are from time to time recorded. Such instances are never i heard of in time to permit of an exact ’ inquiry as to the nature of the disease being made, and they must therefore be taken as doubtful. But there is no doubt at all of the fact that blackleg is a disease of cattle under two years old, and that the majority of its victims are calves of a fe .v months old. A fact in history of blackleg, which is well known to practical men, refers to the localisation of the disease. Certain lands and'particularjdisfcricts enjoy an unenviable distinction as places where blackleg is always certain to occur among calves which are put to graze on them, although it often happens that adult cattle may be fed on the land without risk. Some pastures on which black leg constantly occurs are on strong retentive soil, where the herbage is luxuriant, but poor light soils with scanty herbage are not ‘ exempt; and it cannot be said that the localities in which the conditions are favourable to the development of the disease can be distinguished by their geological or botanical features. Investigation into the circumstances of soil and climate in places where the causes of black leg are evidently concentrated might lead to the discovery of certain characters common to all of them, and possibly connected with the occurence of the disease ; but at this moment no evidence which is available connects blackleg with any climatic or dietetic conditions. That the blood in the animal affected with black leg has undergone some change of structure, is quite certain from the observed morbid appearances ; but the exact character of the change and its causes have not been made out. In the fluid which is effused into the structures in which the affection is to some extent localised, generally one hind-quarter,many micro-organisms are detected, most of them the ordinary organisms of decomposition ; and their presence cannot be accepted as evidence of the possession of any influence in the production of the malady. In the tissues of the diseased part a microbe is found often adhering to the muscular fibres, and this organism, which is a bacillus, is considered by MM. Cornevin and Arloing>s the special infecting agent; but the evidence on this point would hardly satisfy the modern bacteriologist, and further experiments are necessary. In districts where black quarter has a constant existence, the stockowner expects to lose a certain percentage of his calves every year, and if the losses do not exceed 5 per cent., he accepts the infliction without complaint. This fact in itself goes a long way towards proving that the disease is not spread by infection, or by association of diseased with healthy animals, But, on the other hand, ithas been experimentallyproved that the affection is readily communicated by means of the introduction of the morbid products of the disease beneath the skin of a healthy susceptible animal ; it is therefore clear that no dissection of calves dead of the disease should be made in the pastures where other calves are grazing. The risk of contagion is probably very slight, but there is at least a possibility of some of the morbid matter coming in contact with a slight wound in the skin, and nothing further would be required for fatal inoculation. A probable cause of the extension of black leg to healthy cattle is referred to in the Agricultural journal just issued by Miss J Ormerod, who writes to call attention to

the possible occurrence of blood poisoningamong cattle infested with warbles, from the absorption of the foul matter which is contained in the cyst in which the warble maggot passes its existence. Miss Ormerod remarks that she has information from a tanning firm of a skin of a yearling having been brought in which was covered with warbles. The person bringing the skin considered that the beast had died from black leg. Other hides similarly infested had also been received, and the same story of the animals from which they had been taken having died of black leg was told. The occurrence of blood poisoning as a result of the introduction into the blood streams of septic matter from the warble cyst must be allowed to be probable ; but there is also some reason to apprehend that the warble fly, and also the ordinary gad-fly, when attacking cattle, may be to some extent the agents by which infective matter may be transferred from diseased to healthy subjects—in fact, that the ovipositor of one insect and the nippers of the other may become charged with virus, and act as efficient inoculating needles. Symptoms of black leg are so well known in the districts and in the lands where it is frequent, that there is not much risk of any mistake being made. The stricken animal is dull and moves stiffy one hind leg, or occasionally a fore limb is advanced with much difficulty. Shortly after these pre. monitory symptoms are noticed, the calf is found standing or lying in a corner of the field or in a ditch, wi- h evident swelling over the loins and quarters, and on pressing the swollen part a characteristic crackling noise is distinguished. This symptom is always accepted as sufficient to indicate nature of the disease, and it is expected that the animal will be dead in the course of the next twenty-four hours ; and it is generally the case that a fatal termination occurs as expected. Treatment of black leg is seldom attempted. Indeed, when the disease is actually developed, the animal may be looked upon as moribund. The cures of black leg which are recorded are extremely few, and the chief attention of the stock owner is directed to the adoption of preventive rather than curative measures. Setons in the dewlap are old-fashioned means of prevention, which certainly deserve consideration on account of the success which appears to result from their use. Salines in the food are also very useful, and in any case perfectly harmless. A little ground oil cake or meal, with half a drachm of nitre mixed with it, may be given to each animal daily for a few days, and repeated at intervals, and those who have tried the method speak very favourably of it. Lastly, there is the plan of protective inoculation, to which we referred in a recent article. This method, however, is still on its trial, while the others have ctood the test of years.

On the Treatment of Anthrax.

Sik,—Anthrax is a fatal and almost intractable disease that seems to find a place in almost every country. In India it is computed that at its outbreak in an acute form almost every case will be fatal, and probably fifty per cent, of the later cases, when the disease is beginning to die out, will recover. Having been a heavy personal loser by anthrax, and having tried unsuccessfully every recommended allopathic remedy, I turned to homoeopathy. It so happened that last year I met withseveral cases of malignant sore throat and laryngitis which defied ordinary treatment, but which yielded readily to the cyanide of mercury. This drug was so successful that I determined to try it in anthrax. It succeeded sufficiently to induce me to continue the experiments. I have within the last three months cured three acute cases of anthrax with this drug, one case being of a very virulent type. Cyanide of mercury was given in three-grain doses every hour, or two or three hours, according to the severity of the symptoms. As anthrax is now making great havoc, among cattle in England, I should like much to see this remedy tried. If it fails, it is but another added to the long list of failures; if it succeeds in obtaining a fair per centage of cures, it would be very gratifying. One great advantage of the drug is its speedy action, apparent in from six to twelve hours. Should I meet with more cases, I purpose injecting cynide of mercury in onegrain doses sub-cutaneously, instead of the usual exhibition. In the cases alluded to, after the malignant symptons had subsided, there still remained a slight difficulty of breathing, which yielded in one instance to bryonia 1, in twenty-drop doses ; and in another a slightly increased temperature, with yellowness of the mucous membrane, for which gelsamen 1, in ten-drop dose 3, proved curative. Should my treatment be tried, I should be very glad to hear the result. G. 'W. Deane, Captain, 18th (Duke of Connaught’s) Bengal Lancers Bareilly, N. W. Provinces, India, May 17.