This section is from the book "The Farmers Ready Reference Or Hand Book Of Diseases Of Horses And Cattle", by S. C. Orr. . Also available from Amazon: The Farmer's Ready Reference;.
A curb is a sprain of a ligament (calcaneo-cuboid) at the back part of the hock. It frequently occurs in attempting to back a heavy load, especially in deep mud or snow. It also comes from jerking the bridle-bit and throwing a horse back upon his haunches. Some hocks are loosely built and naturally rounding on the back part; such are more liable to curb than those of a more compact form.
Symptoms. - There will be more or less enlargement at the back part of the hock and it will be hot and painful upon pressure. There will also be lameness and the horse will be inclined to walk upon the toe.
Treatment. - The first thing to do is to have a shoe put upon the foot of the lame leg with heel calks three-quarters of an inch or more high and no toe calks; this is to relieve the injured part of all tension and is imperative. The next step is to apply cold water to the part until all inflammation is removed In some very mild cases this is all that is necessary; but if lameness or the enlargement either one continues, apply the biniodide of mercury blister. Allow the high-heeled shoe to remain on for four or five weeks or until all lameness ceases. If necessary, repeat the blister.