PULPY KIDNEY.

Press, Volume LXVI, Issue 20095, 26 November 1930, Page 16

PULPY KIDNEY.

INVESTIGATIONS ABROAD. I Keports from stock inspectors in the South Island are to the effect that in comparison with recent years, the mortality among lambs has been much lower. Exactly the cause of this is uncertain, but it is a fact that feed has been scarcer and ewes have not had the usual milk supply. The two facts have been associated in the past —i.e., lamb mortality is coincident with an abundance of feed —and this year's experience would appear to confirm this theory. In the latest issue of the "Victorian Journal of Agriculture" the senior veterinary officer (Mr b\ X. Johnstone)., arrives at similar conclusions. He I points out that the disease_ among fat lambs known as "pulpy kidney" has increased considerably. The deaths occur at different ages in different countries, which appear to coincide with the period at which the lamb receives the richest food. The fattest and be=t lambs die quite suddenly. Usually they are found dead in the morning, and only very rarely is one noticed to be sick before death. The. cause is believed to be one of over-nutrition. The increase in deaths in Victoria (says Mr Johnstone) seems to have been coincident with top-dressing of pastures and the destruction of rabbits, which have improved the carrying capacity of the land without a proportionate increase in the number of stock carried. In New Zealand the deaths occur there at from two to four weeks of age; in Victoria at three to six weeks. Ordinarily, twin lambs rarely die of this disease, probably because. thoy are not in such good condion as single lambs, having mothers with a large supply of milk. Occasionally lambs die.on pasture which does not appear to be particularly rich. But on examination they arc always found to be in very forward condition.

TJsuallv a post-mortem examination reveals the kidneys to be like a red jellv-like pulp, the central part being less affected and sometimes quite firm. Both kidneys are affected in all cases. Sometimes the kidneys appear mottled, due to hemorrhage in the organ. The liver is intensely congested with blood. The heart sac. is distended to a variable degree with straw-coloured blood. If the lamb has been dead some time, clots of fibrin ar.- present. On cutting into the heart itself, slight hemorrhage under the lining membrane of the lower cavities is found. Compulsory exercise seems to have a beneficial effect. This is difficult to carry out, unless the lambs and their mothers are kept separately. Over-stocking or placing on poor quality pasture, or temporarily starving by yarding for 12 to 14 hours every fourth day, also appears to check the incidence of the disease. f i he condition of the ewe at lambing lias some influence. Mothers that are strong and healthy have a full supply of milk, and rear their lambs much better.

Bloating. Miiuy deaths among lambs attributed to pulpy kidney (states Mr Johnstone) are actually duo to other causes. Bloating is a danger which should lie kept constantly in mind by the farmer where luscious feed, such as lucerne, or even young grass, or young crops of oats or wheat, are used for depasturing ewes and lambs. When stock are kept on these foods constantly, there is not much to be feared. It, is when they are run on the crops for a brief spell, or when such foods arc cut and fed to them | that there is danger. The food is attractive and appetising, and being unaccustomed to it, the lambs are apt to eat too greedily. This type of food ferments easily, and forms largo quantities of gas in the rumen. The animals cease to feed, stand motionless, gather their feet under them, arch the back, and stop ruminating. Considerable swelling of the abdomen occurs. This is most marked in left side, particularly before death. The abdomen walls become tense, mid can be pressed in only with difficulty. Inspiration becomes difficult. The membranes of the mouth become blue in colour, and finally the animal dies in convulsions. In acute cases the gases form so rapidly that sultocatiori may occur within a few hour*. In mild eases the forequarters of the animal should bo elevated, and the flanks vigorously massaged. Driving up a hill has much the fame effect. If a largo amount of gn' has formed before the animal is noticed the rumen should be punctured thrmgn the left flank, and the gas allowed to escape. Bloating is always due to careless feeding, and can "bo prevented with proper care and attention. Since clovers and lucerne and young rapidly growing crops or grasses are most dangerous, animals should be allowed to run on such pasture only alter tliev have received some dry teed, or ha\e fed on less luxuriant foods. Thev never should be lett long in dangerous pasture, and should lie kept moving whilst on it. If freßhly cut green feed is being given, it should be supplied in small rations, and should be mixed with dry feed before being spread out for the sheep.