Splints of heavy leather or of thin pieces of tough flexible wood are placed on each side of the leg and firmly held in position with bandages.  Bandages may be put on in layers and a coating of glue applied over each layer if this is thought necessary.  The advantage gained in using glue or other adhesive materials is that the cast thus formed is more rigid than where such material is not employed.  On the other hand, all elasticity is lost as soon as the cast adapts itself to the contour of the extremity, and because of this rigidity, it is doubtful if anything is gained by the incorporation of glue, except in the way of added strength of the cast.  Since the animal does not walk upon the broken leg, it is possible to employ splints of suitable materials which are retained in position without glue and frequent readjustment of a part of the immobilizing apparatus is possible.  This is impossible with casts.

In compound fractures, provision ought to be made for dressing the wound of the soft structures.  This entails adjusting the splints in such manner that one splint may be retained and others removed for dressing the wound and readjusted as often as wound dressing is necessary.

Splints.

By this term is meant a condition where there exists an exostosis which involves usually the second (inner small) and third (large) metacarpal bones.  While an exostosis involving any one of the splint bones, even when directly caused by an injury, is called a “splint,” the term is employed here, in reference to exostoses not due to direct injury such as in contusions.

Etiology and Occurrence.—­This condition is one wherein there is osseous formation following a periostitis and the region of the upper portion of the second (inner small) metacarpal bone is the usual site of the exostosis.  There is incited an inflammation of the periosteum at the site of the interosseous ligament which attaches the small to the large metacarpal bone.  This ligament is involved in the inflammatory process, and according to Havemann, whose view is supported by Moller, this inflammation is the origin of the trouble.

Various theories attempting an explanation of the frequent affection of this one certain part so regularly involved have been offered, but no proof of the correctness of any exists.  It follows, however, that splints occur in young animals; that the affection seldom starts in subjects that are ten years of age or older, and that when the exostosis has formed, lameness usually subsides.  Anything which will cause undue strain or irritation of the metacarpal bones in young animals, is quite apt to result in a splint being formed.  Concussion such as is caused by fast work on hard roads, or work on rough or irregular road surfaces which cause unequal distribution of weight, will cause splint lameness and exostosis follows.

[Illustration:  Fig. 16—­Posterior view of radius (right) illustrative of effects of splint.  Note the extent of exostosis.]