340 DISEASES OF THE HORSE'S FOOT 



of great importance to the surgeon. It enables him when 

 operating to distinguish with some degree of certainty 

 those portions of the cartilage which are healthy and those 

 which are not. 



(b) Necrosis of Tendon and of Ligament. — This compli- 

 cation of quittor is, as we have said before, treated by 

 other writers as a distinct form of the disease, and de- 

 scribed by them under the heading of Tendinous Quittor. 



This simply means, of course, that the diseased process 

 has extended to either of the flexor tendons, to the tendon 

 of the extensor pedis, or, perhaps, to the ligaments of the 

 pedal articulation. 



Of the flexor tendons, the perforans is the one commonly 

 attacked, by reason, of course, of its more superficial 

 position. At times, however, especially when its aponeu- 

 rotic expansion is diseased, the necrosis of the perforans 

 spreads until the aponeurosis is eaten through and the 

 phalangeal sheath penetrated. Septic materials gain 

 entrance thereto, and commence to multiply. In this way 

 the flexor perforatus is invaded, and comes to share in the 

 diseased process. 



The extensor pedis is usually attacked by extension of 

 the disease from a necrotic cartilage, or results from the 

 infliction of a severe tread in a hind-foot. In this case the 

 diseased structure has nothing between it and the articula- 

 tion, the synovial membrane in one position actually lining 

 its inner face. The result is that a condition of synovitis 

 is easily set up, and the case aggravated by that and by 

 arthritis. 



With the flexor tendons attacked pain is always very 

 great, and lameness is excessive. This, however, is not 

 sufficiently characteristic to enable us to determine the 

 precise seat of the necrotic changes. Later, however, a 

 tender but hard enlargement made its appearance in the 

 hollow of the heel, which enlargement, later still, became 

 soft and fluctuating. At this stage there is also consider- 

 able swelling along the whole course of the tendons, as 

 high up as the knee or the hock. The foot is carried 



