In coming to this decision the veterinary surgeon must be guided by noting in the wall the points of exit of the nails.  Should the nail adjoining the position already pronounced to be tender have come out at a higher point than the others, it may be assumed that at a lower position in its course through the horn it has gone near the sensitive structures without actually penetrating the horny box, and that in the course of a day or two the sensitive structures involved will accommodate themselves to the pressure thus inflicted.

If, on the other hand, symptoms of tight-nailing show themselves in an animal with good sound feet, then there is no objection to be raised against having the shoe at once removed.  Should the offending nail be definitely detected, then the shoe may again be put on, and that particular nail omitted from the set.

B. PUNCTURED FOOT.

(Pricked Foot—­Nail-tread—­Gathered Nail.)

Definition.—­Under this heading we propose describing wounds of the foot occurring in the sole or in the frog, and penetrating the sensitive structures beneath.

Causes.—­These we shall consider under two headings: 

1.  Wounds resulting from the animal himself ‘picking-up’ or ‘treading’ on the offending object.

2.  Cases of pricking in the forge.

Those occurring under the first heading are, of course, purely accidental.  In the majority of cases, the object picked up is a nail; but similar injury may result from the animal treading on sharp pieces of wood or iron, on pieces of umbrella wire, on pointed pieces of bones, broken-off stable-fork points, sharp pieces of flint, etc.  The same accident may also occur in the forge as a result of the animal treading on the stumps of nails, from treading on an upturned shoe with the stumps of nails in situ, or from treading on an upturned toe-clip.  It may also occur from an accidental prick with the stable-fork when ‘bedding up,’ or from casting part of a shoe when on the road and treading on the nails, in this case left sometimes partly in and partly out of the horn.

’Serious wounds of this description are also met with in animals engaged in carting timber from plantations in which brushwood has recently been cut down.  This is, of course, from treading on the stake-like points that are left close to the ground.  Hunters also meet with the same class of injury when passing through plantations or over hedge banks, where the hedge has just been laid low or cut down.

’Agricultural horses also meet with severe wounds of this class from treading on an upturned harrow.’[A]

[Footnote A:  Journal of Comparative Pathology and Therapeutics, vol. iv., p. 2.]