THE HORSE’S FOOT. 
493 
rior half of the coronary to the semi-lunar crest, and in its 
transverse axis extends from one retrosal process to the other ; 
the inferior portion of this synovial bursa covers the plantar 
aponeurosis in its whole extent. Sometimes, again, the punc¬ 
turing body penetrates as far as the bone; sometimes the navic- 
cular; at others the os pedis, and sometimes even penetrates into 
the articulation. 
II. Symptoms .—They vary according to the seat of the lesion, 
its depth, the mode of action of the penetrating body, length of 
time it has remained in the wound, and the nature of the lesions 
it has made; all conditions which may change the characters of 
the disease from a first degree, when the animal shows no evi¬ 
dence of pain, to the extreme point where its life is in danger, 
and even ends in death, by the excessive local alterations and the 
sufferings accompanying it. 
Often the first point which assists in the diagnosis of the case 
is the history. The driver who lias seen the horse become sud¬ 
denly lame, has examined the foot and found a nail more or less 
deeply; at others, it is the surgeon who yet finds the nail in 
its hiding place. The exploration of the part shows with cer¬ 
tainty the nature of the lesion, the direction and depth of the 
wound, as well as the physical condition of the body which has 
made it, and all circumstances which allow a positive diagnosis 
to be made. 
Quite often the nail is no longer in the foot; sometimes it has 
left its mark—an opening which can be explored ; often this is 
not visible at first sight, though the wound may be even deep ; 
this is when the injury to the hoof has been very slight, and when 
the hoof has retracted on itself by its elasticity, or when the 
opening is concealed by the dirt of the streets. It must be re¬ 
membered that sometimes the penetrating body remains broken 
in the soft tissues after its entrance through the hoof. If the 
accident is recent, only a little blood may be found—liquid or 
coagulated—over the wound ; later, some serosity, more or less 
purulent, is observed; the pus is white or black, sometimes 
mixed with synovial fluid ; sometimes there are granulations on 
the bodies of the wound which protrude over the edges, com- 
