Farmer and Stockbreeder

Auckland Star, Volume LIX, Issue 200, 24 August 1928, Page 13

Farmer and Stockbreeder

(Specially Written for the "Auckland Star-")

BRAXY-LIKE DISEASE.

ASSOCIATED WITH LIVERFLUKE. RESULT OF HAWKE'S BAY EXPERIMENTS. (By SUNDOWNER.) For some seasons past particular areas of Hawke's Bay have been subject to a disease amongst sheep which has caused considerable loss and anxiety to farmers. Because of the similarity of some of the conditions after death to those accompanying braxy, this disease, for want of a better name, has been termed "braxylike disease," but in view of the findings resultant on recent investigations by the Stock Department's veterinary officers, it will probably shortly be given a more accurately descriptive name. The investigations, which were jointly conducted by Mr. C. S. M. Hopkirk, B.V.Sc.. and Mr. E. E. Elphick, M.R.C.V.S.. departmental veterinarian at Hastings, were fully described in the "Journal of Agriculture" of September last, but as many interested farmers appear to be ignorant of the facts as there stated, it will be of interest to briefly summarise the results. Few Warning Symptoms. The symptoms of this disease do not give the farmer much warning that all is not well with his sheep. He may go round his flock and find all apparently healthy, and yet, next morning, or even half an hour later, may find some of his best-conditioned sheep dead where they have been lying peacefully chewing the <ud. That death rapid, and probably painless, is illustrated in the fact that there is seldom any indication of the sheep having struggled. Usually sheep in high condition are mostly affected, and the disease can be found in both sexes and all ages.

Similar "Black" Disease in Australia. In Austral l '", a somewhat similar trouble is decimating the flocks in the Wajsrga district, rnd a writer in an Australian periodical recently suggested that it was caused through leaving sheep overnight on luscious feed, the generated gases from which caused a distension of the stomach, which pressed on and affected the heart or lungs. He cited in support of his theory that sheep removed nightly to sparsely-grassed hill paddocks we' not so subject to the trouble as those left continuously on rich feed. Dr. Dodd, who investigated the trouble in New South Wales, termed it "black" disease, because oi the blackened appearance of the skin in the affected animal* immediately after death. A Companion of Fluke. One peculiarity noticed by the Hawke's Bay investigators was that this trouble was most pronounced amongst sheep in areas wlr e fluke was known to l>e present, and its association with fluke was further supported when it was found by post ;ortem examination that all the organs of the dead animals were nori mallv healthy with the exception of the liver. Diseased Patches in Liver. Of course, during the boring operations of the invading fluke, these set up an I inflamed condition both in the bowel, ! from which they penetrate to the liver. ! and in the liver itself, through which j they search for a duct in which to develop to maturity. This inflammation caused by the fluke, however, was entirely different from the liver condition set up by what the investigators believe to be the microl>e causing this braxy-

like disease, although it was found to occur in tlie burrows made by the invading fluke. The Bacillus Identified. These necrotic, or mortifying, areas in the liver were found to be caused by an organism known as bacillus oedematicus, which generates a poisonous fluid or toxin, which causes rapid death. Cultures made from this bacillus killed guinea pigs in a very short time when introduced under the skin per medium of a hypodermic syringe, and produced exactly the same symptoms as those observed in the affected sheep. Feeding With Germ Does Not Cause Infection. Experiments were then made in feeding this bacillus oedematiens to normally healthy sheep, but no ill-effects were observed. This made the veterinary officers believe that, of itself, the bacillus had no means of penetrating the organs and gaining a footing in the animals tissues. It was observed, also, that deaths took place only during the periods when sheep were usually becoming infected with young flukes. Putting two and two together in the ordinary way, the investigators came to the conclusion that the germs must be picked up by the sheep while grazing, and, finding a perforation through the upper bowel and thence into the liver made by the young fluke, followed this prepared passage and so established themselves, with the resultant rapid demise of the animal. Bacillus Multiplies in Dead Sheep.

Although at death it was found that no considerably area of the sheep's liver was affected by these germs, within a few hours of death, when the red and white corpuscles could no longer wage their war against the intruders, the bacilli spread to every part of the carcase and multiplied in their millions. How Soil Becomes Infected. It is apparent that this bacillus oedematiens has considerable vitality and can live for long periods apart from its host, the sheep. As is usual on many farms where there is only one pair of hands to do all the work, the sheep which died of this disease were perhaps plucked, but apart from that the carcases were allowed to lie and rot, transferring the deadly germs which they contained in countless millions to the soil and pasture and thence to the water courses also. Following this cycle it can easily be imagined how sheep continued to become infected year after year with this mysterious disease, while the desperate farmer watched his valuable animals die.

Preventive Measures. Logically, one can see tnat there are two steps which should be undertaken to rid the country of infection, if the findings of our Stock Department investigators are accurate, and there is no reason to believe otherwise. First of all the country should be rid of the small water snails which inhabit the water courses and which act as host for the liver-fluke during part of its life cycle. This can be accomplished bv draining all swampy places -where the snail breea«, and while this draining is in progress these spots should be topdressed with copper sulphate, otherwise known as bluestone. at the rate of 2Slb of the powdered chemical to the acre. This treatment should take place in the summer time, when the swamps have shrunk in size and the snails ..re breeding. As far as possible keep sheep out of these infected swamps until they are thoroughly cleaned up, and treat all sheep in fluke-infested areas with carbon tetrachloride in 1 c.c. doses, which can be procured in capsule form. This drug effectually eliminates the flukes.

which mar be infesting the sheep, and naturally "puts a stop to their further propagation. Disposal of Carcases. Then there is the matter of the disposal of the carcases of sheep which have died from this disease. Of course, they should not on any account be allowed to lie and impregnate the soil and drinking water -with their germs. They should either be burned where they lie, or buried sufficiently deeply enough to prevent the germs coming in contact with the grass eaten by the stock. "Although the Department do not claim that the last word regarding this disease has been said, the farmer who follows out tee procedure here recommended will have little to fear from deaths from this cause in future, for the results have been proved by trial.