DISEASES. 725 



Ions tracts, -vrhicli open on the cartilage, make their appearance. 

 At times the woimd closes ; but, after a short interval, opens again, 

 or another forms at another point. There is then a repetition of 

 the same course of treatment by caustic apphcations — but gener- 

 ally this indicates a complication, and suggests the propriety of 

 an operation. The injections are generally successful, however, 

 and most certainly so if the caries occupies the posterior parts of 

 the cartilage. They may even succeed in the anterior parts, when 

 the animal is young and of good constitution. But if the cartil- 

 age has already become partly ossified, the caustic is irregular in 

 its action, and the result becomes doubtful. If the caries is deep 

 and extensive, and especially if the necrosis extends through and 

 through to a point corresponding to the synovial capsule of the 

 articulation of the last phalanx; or if the necrosis exists on the 

 internal face of the cartilage, where it covers that structure, then 

 the repeated injections of Villate's, or of any other caustic, may 

 be followed by serious complications. An old or comj)licated caries 

 will offer an increased resistance to the treatment by liquid caus- 

 tics, in proportion as there is more or less difficulty in bringing 

 them in dii'ect contact with the necrotic points. 



The thu-d method of treatment is that of the removal of the 

 cartilage. This operation, first recommended by Lafosse, Sr., in 

 1754, was often performed by his sou, and may be considered one 

 of the most valuable results of the application of anatomical 

 knowledge to the practice of veterinary surgery. This operation 

 was also performed by Bourgelat and his students, by Girard, 

 Hurtrel, D'Arboval, and was principally studied and described by 

 Renault. In Germany, notwithstanding the writings of Langen- 

 bacher, Dieterichs and Hertwig, it did not meet with approval, 

 and EngHsh veterinarians seldom, if ever, resorted to it. At pres- 

 ent, even in France, it is seldom performed, except in case of fail- 

 ure by the caustic injection treatment, and this is often the case 

 where the disease is situated in the anterior part of the fibro- 

 cartilage, where the cartilaginous tissue predominates, or where 

 the vitality is diminished, and above all, where ossification has 

 taken place. It is an operation of the greatest delicacy, and ac- 

 companied with great risks on account of the proximity of the 

 joint of the foot, and it requires an experienced operator and 

 thorough practitioner to justify a hope of successful results. It 

 consists in the excision, by layers, of the diseased cartilage, and 



