that the
penetrating object has gone deeper, It may be distinguished from puncture
of the plantar aponeurosis alone by the fact that there is an excessive
discharge of synovia from the wound. This, as it escapes, is at first clear
and straw-coloured. Later it becomes cloudy and flaked with pus, and shows
a tendency to coagulate in yellowish clots.

Pain and accompanying fever is most marked, much more so than when the
plantar aponeurosis alone is injured.

Should the original wound be insufficiently enlarged, or should its opening
become occluded by the solid matters of the discharge, then this condition,
like the last, ends in the formation of fistulous openings in the heel.
These make their appearance as hot, painful, and fluctuating swellings in
that position. Later they break, discharge their contents, and leave a
fistulous track behind.

_(e) Fracture of the Navicular Bone_.--Penetration of the substance of
the navicular bone, _without_ its fracture, adds nothing to the symptoms we
have described under puncture of the bursa. That the bone has been reached
by the penetrating object may be detected by probing. This, however,
must be performed with care, especially if a flow of synovia is absent.
Otherwise, the wound, as yet, perhaps, superficial enough to avoid
penetrating even the bursa, is made a penetrating one by the probe itself.

Fracture of the navicular bone is fortunately rare.

_(f) Penetration of the Pedal Articulation and Arthritis_.--This we shall
consider in greater detail in Chapter XII. It is sufficient here to state
that the condition may be suspected when a hot and painful swelling of the
whole coronet makes its appearance. There is at the same time a diffused
oedema of the fetlock and the region of the cannon, sometimes extending
upwards to the whole of the limb.

Of all the complications to be met with in punctured foot this is the one
most to be dreaded. The intense pain and the high fever render the animal
weak and thin in the extreme. The appetite becomes impaired, sometimes
altogether lost, and the patient in many cases appears to die from sheer
exhaustion. Added to this is always the extreme probability of the wound
becoming purulent, and later the dread of general septic infection of the
blood-stream ensuing, and death resulting from that. Even with the happier
ending of resolution, anchylosis of the joint and incurable lameness is
more often than not left behind. (See Suppurative or P