The effect of thyroxin on the cutaneous system in the sheep.

Abstract

On January 11th, of this year, a thyroidectomized lamb, about eight months old, showed great muscular depression and in order to save its life the subcutaneous administration of thyroxin was begun. Half a milligram was injected every second day for one week; then as recovery began the dose was reduced to 1/8 mg. and later to 1/8 mg. In about ten days the animal showed great improvement as was anticipated but after about a month's treatment it was observed that the wool was beginning to fall out in patches and this effect was not expected. The shedding of the wool was first noticed on February 7th; photographs were taken every second or third day to show the progress of the denudation and by February 27th—in about 20 days—the whole animal was bare to the skin with the exception of the head and neck. Considerably later the wool from this area also was shed.

To find out whether thyroxin would have the same effect on the normal sheep, two were selected and each received 1/4 mg. subcutaneously every second day beginning on February 13th. In about a month one of these reacted as the thyroidectomized lamb had done, although the shedding of the wool was not so extensive, but the other showed no effect, although later the dose for this animal was increased to 1 mg. every second day and continued till April 27th.

Following thyroidectomy the fleece becomes coarse and ragged giving the animal a tattered, unkempt appearance but the complete and rapid denudation produced by the subcutaneous injection of thyroxin has not been observed in our flock to follow removal of the thyroids. A more detailed statement will follow.