210 DISEASES OF THE HORSE’S FOOT 
the same manner a prick to the frog that, although deep, 
is mainly concerned with penetrating the plantar cushion 
may also be classed as simple. 
Deep or penetrating when driven with sufficient force or 
in such a direction as to injure structures whose penetra- 
tion is calculated to give rise either to serious constitutional 
disturbance or to permanent lameness. In this category 
we may place injuries to the terminal portion of the per- 
forans, puncture of the navicular bursa, fracture of the 
navicular bone and penetration of the pedal articulation, 
and splintering of the os pedis. 
Symptoms and Diagnosis.—While discussing the symp- 
toms and diagnosis, we will still continue to consider our 
subject under the two headings of (1) accidental ‘ gather- 
ing’ of some foreign body, and (2) pricks inflicted in the 
forge. 
In a few cases belonging to the former class the 
veterinary surgeon is fortunate in obtaining a direct history 
of the injury. The driver has seen the animal go sud- 
denly lame, and has examined the foot for the cause. 
Hither the nail has been found embedded in the horn, or 
the puncture it has made detected, and the matter has been 
reported. The foot is then explored and the full extent of 
the injury ascertained. 
In many cases, however, it so happens that no evidence 
of the infliction of the injury is forthcoming. The 
‘momentary lameness occurring at the time of the prick 
is unreported at the time by the attendant, and the horse 
for a time goes sound. It is not until the changes set up 
by the subsequent inflammatory phenomena make their 
appearance, and lameness results, that attention is called to 
the foot. When this happens there has, as a rule, been 
time for pus to form around the seat of puncture—a matter 
of about forty-eight hours. 
The horse is now brought out for the veterinary sur- 
geon’s examination, going distinctly lame. If the case is 
well marked there may then be noted by the man of 
experience many little signs pointing to the foot as the 
