In some cases, however, lameness is present.  During the early stages of the growth’s formation it is but slight, increasing as the keraphyllocele enlarges.  Should this be the case, other symptoms present themselves.  The coronet is hot, and tender to the touch, sometimes even perceptibly swollen, and percussion over the wail is met with flinching on the part of the animal.  In other cases one is led to suspect the condition by the prominence of the horn of the wall of the toe.  This is distinctly ridge-like from the coronet to the ground, while on either side of it the quarters appear to have sunk to less than their normal dimensions.  We believe this to be an illusion, as a ridge of any size at the toe readily gives one the impression of atrophy behind it, without this latter condition being actually present.

Should this ridge-like formation and the accompanying symptoms of pain and lameness occur after repair of a sand-crack, then keraphyllocele may, with tolerable certainty, be diagnosed.  When these outward signs are wanting, however, and the true nature of our case is a matter of mere conjecture, a positive diagnosis may still be made at a later stage—­that is, when the abnormal growth of horn reaches the sole.  In this case either there is met with when paring the sole a small portion of horn, circular in form, distinctly harder than normal, and indenting in a semicircular fashion the front of the white line at the toe, or solution of continuity between the tumour and the edge of the sole and the os pedis takes place, and the lameness resulting from the ingress of dirt and grit thus allowed draws attention to the case.

Pathological Anatomy.—­With the sensitive structures removed from the hoof by maceration or other means, these growths are at once apparent.  They may occur in any position, but are usually seen at the toe, and they may extend from the coronary cushion to the sole, or they may occupy only the lower or the upper half of the wall.  In places the tumour (or ’horny pillar’ as the Germans term it) is roughened by offshoots from it, and does not always exhibit the smooth surface depicted in Fig. 132.  Commonly, the horn composing the new growth is hard and dense.  Sometimes, however, it is soft to the knife, and is then found to be itself fistulous in character, a distinct cavity running up its centre, from which issues a black and offensive pus.

In a few cases the sensitive laminae in the immediate neighbourhood are found to be enlarged, but in the majority of cases atrophy is the condition to be observed.  Not only are the sensitive structures found to be shrunken and absorbed, but the atrophy and absorption extends even to the bone itself (see Fig. 133).  This latter is a result of the continued pressure of the horny growth, in a well-marked case ending in a sharply-defined groove in the os pedis in which the keraphyllocele rests.  The fact that the softer structures, and even the bone, thus accommodate themselves to the altered conditions is, no doubt, the reason that lameness in many of these cases is absent.