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INSTITUTE OF INSPECTORS OF STOCK OF N.S.W. YEAR BOOK.
TRANSIT TETANY OF SUCKER LAMBS—MIXED SEXES
T. R. Jones, B.V.Sc., Inspector of Stock, Forbes.
On 10th October, 1944, the writer was advised that losses had occurred in a mob of sucker lambs recently delivered at a local meatworks.
History: About 1,000 mixed-sex, crossbred lambs were purchased at public auction at Barellan on 6th October, 1944, and were trucked for Forbes on the following day. They arrived at Forbes on 9th October and were untrucked at about three o'clock in the afternoon. After unloading, a number appeared to be stiff and somewhat "crutchy", but no particular significance was attached to this as the lambs had had a long time in the trucks. They were moved quietly to the yards at the meatworks, taking about four hours to cover the three mile journey. The next morning about fifty (50) were found dead and another 50, approximately, were sick.
On inspection it was found that the trouble was distributed evenly between the sexes, the dead ones were quite dead and the sick were showing symptoms of mineral imbalance. As two blood bottles only were available at the time, blood samples were taken from two only of the prostrate wether lambs; the serum samples obtained from these being forwarded to Glenfield Veterinary Research Station for favour of calcium and magnesium estimation.
After deliberation, the manager of the meatworks was advised to "treat" the lambs instead of bothering with therapy. This was done immediately and three only were rejected on account of fevered flesh; the remainder being passed as fit for consumption.
When in due course a report on the calcium and magnesium estimations was received the following figures were presented:—
| Lamb No. 1. | Calcium | 8.1 mg. per cent. |
| Magnesium | 1.6 mg. per cent. | |
| Lamb No. 2. | Calcium | 6.5 mg. per cent. |
| Magnesium | 1.5 mg. per cent. |
It is claimed that these figures confirmed the diagnosis of mineral imbalance.
Comment: Although mineral imbalance has been suspected in cases of transit tetany in both sheep and cattle for the last five or six years, this is the first opportunity the writer has had of having serum samples analysed. Transit tetany is seen not uncommonly at large unloading centres and at spelling centres, when stock on a long rail journey are unloaded for a few hours, usually watered, and then reloaded. Losses usually are attributed to mallows, nettles,etc., which ordinarily are found in locality of such centres; but owing to the rapidity of action of scavengers it very seldom, if ever, is possible to get to the scene of mortality in time to obtain a serum sample.
The disease is not new, for it is probable that Stewart (1900) saw it, although he allowed himself to be misled by the nitrogen content of the mallow. Dodd and Henry (1922) gave a faithful description of mineral imbalance when they described the symptoms of staggers produced by feeding Malva parviflora. Actually, what appear to be identical symptoms sometimes are seen in sheep grazing on other pastures, such as young wheat or oat crops. Franklin and MacGregor (1944) have shown that hypocalcaemia and hypomagnesaemia can be produced in rams by starvation but they did not refer to associated clinical symptoms such as are seen under normal field conditions. They mentioned weakness and stumbling when rams were driven two hundred yards to a paddock after a period of starvation; and it is quite possible that staggers and shivering, and perhaps mortality, may have been produced by further driving.
References:
Stewart (1900): Ag. Gaz., N.S.W. xi. 1112-1117. Staggers in Sheep.
Dodd and Henry (1922): Ag. Gaz., N.S.W. xxxiii. 653-659, 719-724, 802-806, 883-888.
Jour. Comp. Path. and Therap., xxxv, 41-61. Staggers or Shivers in Livestock. cited by Hurst. E., (1942): "The Poison Plants of New South Wales", The Snelling Printing Works, Pty. Ltd., Sydney.
Franklin and MacGregor (1944): Aust. Vet. Jour., xx. 328-331.