812 CHRONIC INFLAMMATION OF THE KNEE-JOINTS. 



opened at the lowest point. The animal is tied up securely, and an 

 assistant directed to grasp it by the nose. The knee is then raised 

 and flexed as much as possible, and the swelling is opened with a 

 bistoury, the knife being directed downwards and outwards to prevent 

 injury to the deeper seated structures. The cavity is freed from 

 clots with the curette, the animal placed on soft, clean straw, and 

 the wound cleansed daily. Recovery generally occurs in three to 

 four weeks. Hertwig recommends passing a seton through the 

 swelling, leaving it in position for fourteen days, and following this 

 treatment by blistering. 



Although similar treatment may be employed in the synovial 

 form, it is better, if the parts are already aseptic, to puncture with 

 the trocar, using antiseptic precautions, and afterwards inject a 

 solution of iodine. Should this fail, or should purulent inflammation 

 of the sheath of the tendon set in, it may be necessary to lay the 

 sheath open and thoroughly cleanse it. Having regard, however, 

 to the fact that this form of the disease is frequently of a tuberculous 

 nature, treatment is seldom of much value, and animals should be pre- 

 pared for the butcher. As a rule, little can be done for the indurated 

 or horny form of capped knee, unless the tumour is small, pendulous, 

 and has not too broad a base, in which case it can be extirpated, 

 but it is difficult to prevent suppuration and excessive growth of 

 granulations after operation. The introduction of euphorbium or 

 caustics like sublimate and acids into the swelling, is liable not 

 only to injure the articulation but to increase the growth. 



III.— CHRONIC INFLAMMATION OF THE KNEE JOINTS. 



Chronic inflammation of the knee, arthritis chronica, occurs 

 oftenest in horses, and has long been recognised. Cherry described 

 it under the title of " knee spavin." Schrader found the articular 

 surface more or less " degenerated," the cartilage worn away, and 

 exostoses on the bones. He also described ulceration of the cartilage 

 of the joint, necrosis and exostoses of the bones, and anchylosis. 

 According to Cherry, the os lunare and head of the large metacarpal 

 may alone suffer, but the inflammation generally extends farther. 



Causes. Horses with narrow, imperfectly-formed knees, short 

 fore-arms and upright shoulders, appear most predisposed to the con- 

 dition, possibly on account of the peculiarly exaggerated movement 

 in the knee-joint which such formation favours. Russian trotters 

 display this form and action most conspicuously, and also very 

 frequently suffer from chronic carpitis. Cart horses that " dig " 



