CONTRACTED TENDONS IN FOALS. 
583 
generally affects both front legs, often causing the animals to walk with 
the front of the phalanx on the ground, and preventing their standing 
upright. It also develops, though rarely, during the first two years of 
life, and never in such a serious form. 
The cause is at present unexplained. Franck considers it due to 
congenital contraction of the flexor tendons existing at the time of 
birth. Others ascribe it to abnormal position of the foetus in utero, 
whilst Lafosse thinks it arises from disproportion between the stallion 
and mare, the bony framework being excessively developed when the 
stallion is too large. As large animals are especially affected, and as, 
in general, only the phalanges suffer displacement, the cause must lie 
between the point of insertion of the flexor perforans and its reinforcing 
ligaments. There are two possibilities: either the tendons are too 
short or the metacarpus is too long. The first may be referred either 
to defective development or subsequent shortening of the tendons. 
Whether, in such case, the development of the flexor tendons is 
interfered with by the position of the foetus in utero, or whether contrac¬ 
tion occurs, or whether the long axis of the metacarpus is excessively 
developed, so that the tendons are relatively too short, or whether again 
the point of origin of the muscles is abnormal, is for the time at least 
undecided. Perhaps the condition may be caused in more than one way. 
Abnormal position in utero would probably interfere with develop¬ 
ment of the joints and muscular tissue. Increase of pressure on the 
posterior portions of the joints, caused by continued volar flexion, would 
check the growth of bone, while diminution in the anterior portions of 
the joints would favour its production, and thus tend to thrust the 
phalangeal joints more and more into a position of volar flexion, favour 
the development of the disease, and cause it to assume a certain 
resemblance to “ pes equinus ” in man. The rapidity with which the 
condition yields to proper treatment, however, seems to contradict this 
theory. Whether the cause is too little space in the uterus (too little 
liquor amnii), or too narrow a maternal pelvis, need not be considered 
here ; but the frequent occurrence of the disease in pure-bred animals 
appears very remarkable. 
Symptoms. The most important symptom is the abnormal volar 
* flexion in the fetlock-joint. No disease of the tendons or muscles can 
be detected, though they appear tensely stretched when the fetlock is 
upright. Where the condition is well developed, the limb is incapable 
of bearing weight. The new-born foal rears itself up, but cannot stand, 
and may die from local gangrene produced by lying (bed-sores), or is killed 
as a hopeless cripple. Sometimes the animals stand on the front of the 
fetlock-joint, and thus produce serious injuries. Where the appearance 
of the disease is delayed the animals can stand, but move with difficulty, 
