INFLAMMATION OF POSTERIOR LIGAMENTS OF CORONET-JOINT. 
628 
but the tendon of the flexor pedis also. Such strain also results when 
the heels of the shoes become worn down. The condition is favoured by 
work on hard rough ground, especially in riding-horses ; animals with 
upright pasterns and narrow hoofs seem particularly predisposed. 
Gutenacker has recently studied it carefully, and has found osteophytes 
at the points of insertion of the ligaments into the os suffraginis. 
On post-mortem examination the ligaments on the posterior face of 
the joint are found thickened and ossified at their insertions (fig. 229). 
In aggravated cases false anchylosis may occur. 
Symptoms. The disease is in the early stages signalised by lame¬ 
ness when weight is placed on the limb, and by the foot being rested. 
As the ligaments lying behind the coronet bear most weight, and are 
subject to most strain at the time when the limb is directly under the 
body, the horse avoids this position, and in the last phase of movement 
lifts the foot rapidly from the ground. The stride is therefore markedly 
shortened during this last period, and the lameness acquires a certain 
resemblance to laminitis, and especially to chronic navicular disease, in 
which the pastern is also upright. 
A careful local examination will at once dispel any doubts. The 
postero-lateral ligaments, and those lying beside the posterior ligaments 
of the coronet-joint, may be manually examined to detect pain. The 
foot is lifted as in shoeing, and pressure exercised alternately with the 
thumb of either hand. The ligaments lie partly under, partly along¬ 
side, the flexor pedis perforans at the back of the pastern. To prevent 
mistakes, it is well to examine both feet. Sometimes thickening of the 
ligaments can be detected ; occasionally this is of considerable extent, 
and may then best be recognised by allowing the horse to stand on 
the limb ; a comparison should be made with the other foot. The 
diagnosis may further be assisted by throwing a certain strain on the 
ligaments. To do this the foot is lifted and the toe powerfully thrust 
forwards, i.e., in the direction given it by the extensor muscles. 
Fambach found in some cases where the toes were turned in that 
the external postero-lateral ligament was alone diseased. 
In chronic navicular disease pain is produced by pressure in the heel, 
over the navicular bone, but is altogether absent in inflammation of the 
posterior coronary ligaments. Contraction of the hoof is also wanting. 
The fact that symptoms of laminitis, especially increased pulsation, 
cannot be detected, disposes of the third hypothesis. 
When standing, the animal avoids placing weight on the affected 
limb. To prevent stretching the inflamed ligaments, the foot is some¬ 
times rested with the heels on the wall of the opposite foot; or, when 
pain is excessive, it may be held off the ground with the joints flexed. 
Course and prognosis. Inflammation of these ligaments occurs 
