MORTALITY AMONGST LAMBS.

Dominion, Volume 5, Issue 1297, 28 November 1911, Page 9

MORTALITY AMONGST LAMBS.

-—,—ft . "THE WOOL BALL." A LAV TiIEOKV EXPLODED. A paragraph which appeared in this column on October 31 regurdinjt mortality amongst some of tho bigger lamb* in the Alanawutu district, which mortality some experienced farmers suggested was due to indigestion localise of the quimtity of curdled milk found in the digestive organs, drew a theory from a JJnnncvirke correspondent. The correspondent said that to far this season he had found seven dead lambs between the ages of three and five weeks, and on opening each he found that the milk was curdled, but after stirring tho chewed grass, mixed with tho undigested niilk, he found in each case, as in similar eases in past years, a small roll or ball of wool, which is very matted, mixed with the food in the stomach. This ball of wool, the correspondent urged, was the direct cause of the death of the majority of theso big lambs and it was swallowed no doubt when the lamb was sucking its mother. Tho correspondent's letter proceeded as under :—- "The symptoms of lambs afFccte<l with wool-ball are ciuick, heavy breathing, as well as a tendency to being giddy or dazed, and in Hie last stages the 'lamb loses the use -of its logs but will live for hours, although not ablo to stand. In three-fourths of these cases the lamb is found after death; also, as it is 'only a lamb," , the majority of men do. not hold post mortems on such, and probably if they did, iheir wisdom would not have increased to any extent. "In the past fortnight I was lucky enough to find two lambs alive, both down to it and showing the symptoms described above; one, a. twin, with its mother and brother standing close by. I bled by nicking the vein below each eye; it pled well, and to my surprise, after a littlo assistance, was able to stand, and eventually after some 15 minutes of staqeerinpr walked to its mother. I have seen this lamb on different occasions since and now it is nearly as fat as its mate. The other ease was that of a single lamb, wnich I bled from one eye only, and this lamb also .recovered and is now doing well. Both these lambs had been docked, and neither was too fat, this latter fact suggesting that their, illness could not nave been caused through too much rich fowl, thereby causing indigestion; also, neither was swollen or blown, suggesting clover or tutu poisoning. WHAT AN EXPERT SAYS. Mr. C. J. Keakes, Director of the Live Stock Division of the Agricultural Department, under whose attention the correspondent's theories were brought, stated that this mistaken idea regarding" wool balls, had been held by a good maiiy people in the past, but the theory had been proved to bo wrong. The real trouble was acute congestion of the kidneys. ACr. Keakes produced the following report of the Department's officers on the subject, dated 1907:—"Acute Renal congestion (pulpy kidney) in plethoric lambs.—Annually, on certain properties, there is a greater or lesser mortality amongst the best and apparently the strongest lambs, the cause of whi'ch is generally entirely misunderstood. THE SYMPTOMS. There are no symptoms of a prenionltary nature. Usually the lamb, strong in build, fat in condition, apparently a single" lamb, and about a month old, is found dead, lying in a more or less natural attitude. Death generally occurs suddenly—often while playini Occasionally some form of giddiness may bo observed for a few minutes before death, but nothing more definite. POST-MORTEM APPEARANCES. If tho internal . organs be examined immediately • after death they will' be found practically normal to: the. casual observer. There is a considerable amount of sub-cutaneous and peritoneal fat. The functions of the rumen have just begun. to be employed, as evidenced '.by grass., being present. The' ago is constantly from about . four to eight weeks. The fourth stomach contains a quantity of curdled milk, which, although only to be expected, seeing the animal has but recently fed, is frequently, and erroneously deemed pathogenic by the shepherd. Almost with eijunl constancy may be found amongst the contents of the fourth stomach a looso ball of wool and grass, to the presence of which death is most generally attributed. As such n collection of wool is almost invariably found in any lamb's stomach it having gradually accumulated, tl:icugh strands of wool being swallowed accidentally in tho process of sucking the moth- , ers teats, and as it is never, in such a situation as to cause interruption to the passage of ingesta onward« ficm tho stomach, and as there is never any evidence whatever of gastritis, its rrese'nce is totally without significance from u pathogenic point of view. The kidneys i-ib the only constant teat of disease, "and they are readily overlooked. Thev are gviicraily enlarged, dark-coloured," ,i.vl citeii so soft and extremely pulpy that they I cannot be.removed in a complete condition, ireqiiently, if the capsule be ruptured In the manipulation, only a dark pulpy mass may be secured. On removing the capsule the tissue underneath has almost the appearance of a blood-clot duo to the congestion and tho enormous haemorrhage which has occurred in tho substance of the organ. Microscopic' examination shows intense congestion of all the reral capillaries, with extremely liaemorrhagic areas, it being rare to find any part of the organ entirely free from tUe latter. The liver is also generally congested, though hacmorrhagic areas ire much rarer. Tho heart is frequently distended. . . . The pericardium cti,erol ly contains a considerable quantity of clear gelatinous seroiis fluid, varying in quantity from 2oz. to 4oz. Microscopical and bacteriological examination fails to demonstrate the presence of any oi"an isms either in the kidney, liver," Rerfcudial tluid, or the blood, provided the case be examined early after death. THE CAUSE. . It is difficult to state exactly what is the exciting causo of the renal and hepatic congestion, but the predisposing causes are very evident. They are as follow:—The age of the animal—that is the time when tho milk of the mother has begun to be supplemented by herba-e -rich and plentiful supply of' mother's milk, the absence of another lamb to diminish the excessive supply of mother's milk, and good pasture, favouring the production of this rich and plentiful sunply of milk. In other words, all that tends to induce a plethoric condition in the lamb at the age of from i to 8 weeks before it has begun to take exercise far* fllield from the mother, predisposes to this disease. That this is so is proved by the fact that the best and surest preventivo measure to adopt is the docking of the tail when the lamb is about threo weeks old. After castration the disease rarely or never appears in ram lambs, whereas in ewe lambs, especially those docked when about a week or ten days old, it m n y appear later. This means that ample bleeding, by reducing the plethoric condition of the animal, removes the primary predisposing cause of this disease. As to tho actual and exciting cause of the congestion and haemorrhage in the kidneys, it is possible this mny be connected with inability to oliniinato as rapidly as is necessary the urea and other poisonous substances naturally, and then excessively, present in the blood (owing to_ the rich and abundant diet); but this is somewhat obscure. The result of the renal condition, however, is the formation of the pericardial exudato through interference with the blood pressure, and to these conditions together again reacting on the heart is due undoubtedly tho suddenness with which death takes place. THE TREATMENT. Obviously there is no treatment applicablo as a curative niensurn. Prevention, however, is simple, consisting as it does of docking before the danger period of life occurs. In the case of ewe, lambs, which it is necessary to dock early, tho tail should be left sufficiently lons to permit of another joint being removed if found advisable later on, to reduce condition by bleeding, and so prevent further losses bv tho disease.