LIVESTOCK DISEASES: ANTHRAX

Otago Witness, Issue 2167, 5 September 1895, Page 4

LIVESTOCK DISEASES: ANTHRAX

The reported outbreak of anthrax among farm live stock in a North Island district pro. vides an unwelcome subject for eetious consideration by stockowne-s throughout the colony. The actual existence of the formidable malady is only vouched for by Mr Gilruth'fl pronouncement and gue?s as to its origination in importations of bonedust from co'oDie3 wherein the disease prevails. As an official veterinary ex. pert, it is expected of him by intelligent owners of stcck that in the discharge of his duties ho shall follow the example of authoritative practitioners elsewhere, and g'vo particulars of the diagnosis peculiar to an animal disease brought under his notice, together with details of Irs investigations regarding the origin or causation of ths malady. He has left the origination of the InchCiutha swine fever outbreak a mystery and tho post mortem appearances of the animals attacked unspecified, so that he furnished no reliable guido in the future to owners of pigs seized with diseases not muoh dissimilar to swine fever in their outward manifestations. His bare ij>se dixit has, however, brought about the prohibition of imports of pigs from New Zealand to some of the Australian colonies. This of itselE does no"; matter much to pigbreeders, but when a similar off -hand -flat goes forth that anthrax haß broken out among the live stock of a colony heretofore immune from the malady, and therefore not within the knowledge of farmers and graziers, the nature of the attack, the diverse ways aud facilities for its dissemination, and though last, not least, the dapger to which human life is exposed by the careless handling of the carcase i of animals that have succumbed to the disease should have all been pointed out by the Government specialist.

No doubt the official position hat its prestige, but in these progressive days, so far as stockowners are conccrrci, " A daw'e not retk-.ned a religious bird becaiue it k^eps a-cawing Irom a steeple, " and thtreWire liny are properly exacting iv their demands for lull and precise information from those appointed by the authorities to investigate and report upon unusual outbreaks of disease among animals of the farm.

It is not the purpose here to impugn the Government veterinarian's verdict that the malady which has broken out in a district in the North Island among live stock is anthrax, but to allay all doubts on the subject, and at

the same time to impart to owners of stock a knowledge of the symptoms of the dis-ase — in their experiences a new one — and the post mortem *ppeararc?a of tbe victims. I. M'Fadyean, B.Sc, M 8., professor of comparitive pathology, Royal Veterinary College, London, instances anthrax as affording an example of the revolution effected in veterinary notions, regarding the causes of important diseases. He states that not many years ago anthrax was vaguely described in text buoks as a " disease in which there is a sudden change iv the physical characters and physiological properties of the blood," and that it was believed it originated spontaneously, and that cMmatio and dietetic conditions played an important part in its production. •• Furthermore, it was r- girded as a disease that assumed many forms, the tvo commonest in cattle being eplcnic fever *nd blnck-qußrter." These notions have had to be ditcn-ded, for anthrax is now known to hi a disease that has but one cause — viz , the entrance into the body of a vegetable organism — the anthrax bacillus, whilo the so-called black quarter, once regarded as a mere variety or modified form of anthrax, is now known to be a perfectly distinct disease caused by a bacillus peculiar to it, but nevertheless up to a recent date miVakes by professionals in their diagnoses of these diseases were of frequent occurrence.

In his annual report for 1893 Professor M'Fadyean spates that during tbe 12 months viscera from 49 cases of suspected anthrax were forwarded to the Veterinary College nnd submiited.to microscopic examination, "but only 19 were found to be anthrax, and 19 not anthrax, while in the rem lining 11 the extmiaatioa did not justify an opinion as to the cause of de%th. . ". . . In the light of the examinations made in the reiearch laboratory, grave doubts regarding the accuracy of invpectots 1 reports are justifiable. This is pivbably true at all times, but mistakes in diagnosis appear to have been unusually frequent durmg the aumnaex of 1893. For such mistakes there is very little excuse for when an opportunity to make a post mortem soon after death is afforded, there is no difficulty in arriving at a cectain conclusion as to whether a given animal h*s or has Dot been affected with anthrax." As Mr Gilrulh in his investig»tions would conform to the conditions necessary towards a correct diagnosis, a minute but plain description by him of the characteristic symptoms of the disease, and the appearances of the viscera a few hours after the death of the animal and before the carcase became putrid, would' have" been a helpful guide to farmers in cases where animals may be unexpectsdly fouad dead, or that die aft era very brief illness, for which no other cause than anthrax could be assigned.

For the information of stockownera, and in order to enable them to correctly identify cases of anthrax and distinguish them from other animal maladies, the following summary of the views of leading veterinary authorities is submitted. Much has been said and written regarding the characteristic shape of anthrax bacilli wbich would be o£ little use to farmers ai a means of recognising anthrax, but in nine cases out of ten it can be diagnosed by the appearance of the spleen without having recourse to microscopic examination, provided the examination is made within a few hours after death and before the carcase has become putrid, for it is now well known that as putrefaction proceeds the anthrax bacilli disappear. The spleen in anthrax cases, in cattle at least, is engorged with blood of a dark red colour, and softened to such a degree that its substance will almost flow out when a cut is made into it. When this condition of spleen is met with in an animal that has died suddenly, or after a short illness, there is little risk of error in diagnosing anthrax, but when the spleen is normal in appearance the diagnosis "not anthrax" may be made with -almost absolute certainty, even although the circumstances uncW nh'ch the animal has died have crea'cJ a suspicion of that di3ease. Ao regards ' the source of infection it has been ascertained that the anthrax germ in certain circumstances is capable of producing and multiplying spores in soil or water, and when once such spores have been formed they may Ho dormant for many years,, and at the end of that time cause anthrax by being taken into the system of an animal with food or drink, j Such multiplication and spore formation can only take place when the bacilli are freely ei-

posed to the air at a temperature of over GOdeg Fahr, and in the absence of putrefactive bacteria.

In a report on anthrax by Profesior Brown, 0.8., it was pointed out that this destruction of anthrax bacilli which takes place daring putrefaction of the carcase is very important in another rcspaot. The bacilli are no longer detno-ifrtrable in A spleen that hat been allowed to put-efy inside the body, and it was concluded that this disappearance ot the b&cilli wa< real, and not merely apparent. It was therefore concluded that prompt barial at even a moderate depth was a perfectly safe mods of disposing of an animal dead of anthrax. It was pointed out, however, that burial could not be reittd on to destroy the virulence of a carcase, provided spore formation had taken place in it before burial. It must be kept in mind that for the process of spore formation in tin body two conditions are necessary — the first being that; the bacilli shall be placed at a suitable temperature, and the second that they shall be freely exposed (o the air ; but it has been suggested that spore formation may take place in the air passage*, or atimentirj canal, of an animal either betore or shortly, after death, for it isposiible that in th«S9 situations the bacilli might fiad a sufficiency of oxygen, as tb>y would certainly find a iuffiaiontly high temperature, for spore formation.