DISEASES OF THE FETLOCK, ANKLE, AND FOOT. 451 
osteum membrane covering the bone and coflin bone also are subjects 
of the inflammatory process. Neither is this all; in some of these 
cases of peditis acute inflammation of the coffin joint is present, and 
occasionally suppuration of the joint. A mild form of periostitis, 
in which the exudation is in the outer layer of the periosteum only, 
is a more common condition than is recognized generally by practi- 
tioners. Intimate contiguity of structures is the predisposing cause, 
for the disease either spreads from the original seat or the complica- 
tion occurs as one of the primary results of the exciting cause. In 
the severer cases in which the exudate separates the periosteum from 
the bone, suppuration, gangrene, and superficial caries are common 
results. If infiltration of the bone tissues is rapid the blood supply 
is cut off by pressure upon the vessels and death of the coffin bone 
follows. Grave constitutional symptoms mark. these changes, which 
soon prove fatal. 
In the mild cases of periostitis it is by no means easy positively to 
determine its presence, for there are no special symptoms by which it 
may be distinguished from pure laminitis. In a majority of acute 
cases, though, which show no signs of improvement by the fifth to 
seventh day, it is safe to suspect periostitis, particularly if the coro- 
nets are very hot, the pulse full and hard, and the lameness acute. 
In the fortunately rare cases in which the bone is affected with in- 
flammation and suppuration the agony of the patient is intense; he 
eccupies the recumbent position almost continually, never standing 
for more than a few minutes at a time; suffers from the most care- 
ful handling of the affected feet; maintains a rapid pulse and respi- 
ration, high temperature, loss of appetite, and great thirst. It is in 
these cases that the patient continually grows worse, and the appear- 
ance of suppuration at the top of the hoof in about two weeks after 
the inception of the disease proves the inefficiency of any treatment 
which may have been used and the hopelessness of the case. These 
patients die usually between the tenth and twentieth days either from 
exhaustion or pyemic infection. 
Gangrene occurs in the periosteum as the result of excessive de- 
tachment from the bone and compression due to excessive exuda- 
tion. Other parts of the sensitive tissues are subject occasionally to 
the same fate, and at times large areas will be found dead. 
Pumiced sole is that condition in which the horny sole in the neigh- 
borhood of the toe readily crumbles away and leaves the sensitive 
tissues more or less exposed. It is not a complication of laminitis 
only, for it is seen under other conditions. Williams has described 
the horny tissue of pumiced sole as “weak, cheesy, or spongy, like 
macerated horn, or even grumous (thick, clotted).” Crumbling horn, 
when. critically examined, shows almost an entire absence of the 
cohesive matter which unites the healthy fibers, while the fibers them- 
