Foot-Halt, a disorder peculiar to sheep, and which is occasioned by an insect resembling a worm, two, three, and sometimes four inches in length. The first appearance of this malady is manifest by the lameness of the animal: a symptom which increases to so high a degree, as to prevent it from grazing. In consequence of pain, and want of food, the sheep lingers till at length it falls a victim to the disease, unless the worm be timely extracted; an operation that may be easily performed.
As soon as the animal begins to limp, the lame foot should be exa-mined between the close of the claws, where the skin will be found perforated with a hole, through which the insect has worked itself a passage upwards, between the external membranes and the bone. In order to extract the worm, the claws should be moved in contrary directions, for a considerable time, till the insect gradually makes its way to the surface. This simple operation will be fully efficient, without any other application ; and it is certainly preferable to drawing the worm out; as in the latter case there is always danger of its breaking off, and rotting in the sheep's leg, which would materially injure the animal.
The foot-halt occurs more frequently in wet than in dry seasons; generally in the spring and autumn, but seldom in the summer and winter. Sheep that are pastured in high, healthy grounds, are less liable to be attacked by this insect, than those which graze in low meadows, or marshy soils.