176 THE INDIAN JOURNAL OF VETERINARY SCIENCE AND ANIMAL HUSBANDRY [ I, II
(ix) The effect on the blood-calcium concentration of the oral administration of massive repeated
doses of vitamin D is discussed. The observations suggest that the disease may be prevented by
this means by commencing a massive administration of vitamin D a few days before calving.
An important general principle governing the counteraction effects of the calcium controlling
mechanism upon sudden alteration of the normal blood-calcium level appears to have emerged.
(x) The blood-calcium values of normal sheep were observed. It would appear that the normal
variation of blood-calcium is greater in sheep than in cattle.
The association of acute hypocalcaemia with lambing sickness is determined and the identity
of this disease with milk fever established.
The known curative effects of mammary inflation in lambing sickness are also correlated with
a rise in the blood-calcium values. In one case the therapeutic effect of subcutaneous injection of
calcium was tested: The treatment resulted in rapid recovery.
(xi) The calcium values of normal horses were found to be considerably higher than those of
cattle and sheep. In an examination of two cases of transit tetany in mares a pronounced hypocal-
caemia was found. In one case of transit tetany, mammary inflation, and in the other calcium
injection, was followed by complete cure.
CONCLUSIONS.
I. The essential cause of milk fever is an acute blood-calcium deficiency.
II. The specific curative action of mammary inflation consists in raising the blood-calcium
values.
These conclusions are based on the following considerations:—
(1) Milk fever is invariably associated with an acute hypocalcaemia.
(2) The more severe cases correspond with the lower calcium values.
(3) The fall in calcium is approximately coincident with the appearance of the symptoms.
(4) Tetany is a symptom in severe cases of milk fever and the occurrence of tetany is recog-
nised as consequent upon pronounced hypocalcaemia.
(5) Mammary inflation raises the level of blood-calcium in a normal lactating animal.
(6) Mammary inflation elicits a marked rise in the level of blood-calcium in milk fever and
cures the disease; the process of cure, as manifested in the disappearance of the
symptoms, corresponds with the rise of the blood-calcium.
(7) Injection of calcium, exclusive of other treatment raises the blood-calcium concentration
and cures the disease.
(8) Milk fever in cows, lambing sickness in ewes, and transit tetany in mares are all rapidly
cured by mammary inflation and these are the only conditions in an examination of
over 500 samples of blood in which an acute hypocalcaemia has been found.
We have received the following publication from the Ministry of Agriculture
and Fisheries, London :—
RATIONS FOR LIVE STOCK, (Sixth Edition), by the late T. B. Wood,
C.B.E., M.A., LL.D., F.I.C., F.R.S.; Revised by H. E. Woodman, M.A., Ph.D.,
D.Sc. Ministry of Agriculture and Fisheries Miscellaneous Publications, No. 32,
pages 1-62, 1930. [To be obtained at the office of the Ministry of Agriculture and
Fisheries, 10, Whitehall Place, London, S. W. 1.] Price 6d. net, post free.