Fig. 97.—Left Anterior Foot of the Horse: Anterior Aspect.
1, Outer side; 2, inner side.
When we examine its anterior surface or the opposite one, the hoof of the horse has the shape of a truncated cone with the base below and the summit cut off obliquely downwards and backwards ([Fig. 97]).
Fig. 98.—Left Anterior Foot of the Horse: External Aspect.
1, Fetlock; 2, spur or beard; 3, pastern; 4, outline determined by the external fibro-cartilage; 5, acute angle; 6, nipple; 7, quarter; 8, heel.
Viewed on one of its lateral aspects, it may be compared to a truncated cylinder placed on the surface of the section ([Fig. 98]). We particularly call attention to this latter comparison, for it singularly aids us in making a representation of the foot of the horse when viewed laterally.
Notwithstanding that the hoof forms apparently a homogeneous whole, it consists of three parts, which may be separated from one another by maceration. The indication of such disunion, artificially produced, may seem useless. It is not so, however, for this division of the hoof will permit us to carry out the study of the latter in a clearer, and consequently a more satisfactory, way. The three parts in question are the wall, or crust, the sole, and the frog.
The wall is that portion of the hoof which we see when the foot rests on the ground. It is a plate of horn which, applied to the anterior and lateral surfaces of the foot, diminishes in height as it approaches the posterior part of the region. Posteriorly and at each side the wall is folded on itself, and is then directed forwards to terminate in a point, after having enclosed the [frog], which we will soon study.