296 THE EXTERIOR OF THE HORSE. 



The cyst on the internal face, always much smaller, lies upon the tract of 

 the internal lateral ligament of the metacarpo- or metatarso-phalangeal articula- 

 tion. Its symptoms are the same as those of the preceding, but the blemish 

 which it occasions is less grave. 



A propos of the canon, we have spoken of the enormous indurations of the 

 subcutaneous connective tissue which Professor Trasbot designates under the 

 name of fibrous elephantiasis of the members. In the region of the fetlock they 

 acquire at times colossal dimensions. H. Bouley * has seen some that extended 

 from the inferior half of the canon to the hoof, which they enveloped like a 

 hood. Measuring more than a metre in circumference, they touched the ground 

 behind, with the foot in station, and rubbed, in walking, against the opposite 

 member, into which they had made a deep cut. Two tumors of this nature, of 

 which Prudhomme' 2 has given the description, weighed twenty-one kilos, and 

 twenty-seven kilos, respectively. The deep base of these enlargements is ordi- 

 narily formed by extremely-developed vegetations from the periosteum. 



The most common lesions of the fetlock, those which indicate at a glance 

 the excessive function of this articulation and the premature wearing away of 

 the member, are without doubt the tendinous or articular synovial dilatations, 

 which have received the generic name windgalls. 



One of these dilatations, however, that of the synovial bursa, facilitates the 

 gliding of the extensor tendons over the superficial surface of the anterior cap- 

 sular ligament of the articulation, and could with equal propriety be called 

 anterior windgall. In relation to its development, it is absolutely identical with 

 the others. 



It must not be confounded with the anterior cyst, of which we have spoken 

 above. Like the latter, it determines an abnormal swelling upon this region 

 according to the degree of the synovial hydropsy ; but what will always permit it 

 to be differentiated from the preceding is its relative situation with the tendon. 

 In the first case, the tendon is never located upon the surface of the tumor ; in 

 the second, on the contrary, it is most usually the reverse, unless, under the effect 

 of extreme distention, the somewhat weak parietes of the synovial membrane 

 allow some of the contents to escape into the interspaces of the surrounding 

 connective tissue. Before things have gone so far, however, over the middle of 

 the anterior face of the tumor is seen a vertical gutter which renders it bilobed, 

 and which is due to the compression exercised by the anterior extensor tendon 

 of the phalanges. Rarely does the anterior windgall of the fetlock communicate 

 with the articular synovial. Still, such a communication may be present (Kigot), 

 and it is easy of appreciation, for other lateral dilatations will be found coexist- 

 ing with it, pressure on which is integrally transmitted to the former (Bouley). 



The true windgalls are of two varieties : articular and tendinous. It is impor- 

 tant to be able to distinguish them. 



Articular windgalls appear above the fetlock in the form of two small, round 

 tumors, one on each side, tense when the member is in station, and softer when 

 it is elevated. They are situated exactly in the angular space comprised between 

 the border of the principal canon bone and the corresponding branch of the 

 suspensory ligament of the fetlock. It is only when they have attained a large 



1 H. Bouley, loo. cit, p. 580. 



2 Prudhomme, Hecueil de mexlecine vSterinaire, 1844, p. 589. 



