80 VETERINARY LECTURES 



of Clydesdales having a special tendency to it ; and it is frequently 

 found in young horses rising two years old, more particularly in 

 overfed, forced animals. It very rarely occasions lameness, and 

 sometimes disappears without any treatment. If hard feeding is 

 thought to be the cause, it should be diminished, and the animal 

 turned out to grass, after applying a good dressing of green tar to 

 the part. Compression, by means of an indiarubber bandage, has 

 also a splendid effect, but when lameness is present blistering and, 

 subsequently, firing have to be resorted to. 



157. Thorough Pin. — An enlargement of the synovial sac 

 through which one of the tendons passes, and is situated behind the 

 main joint, and in front of the OS calcis, or point of the hock 

 {Plate IX., No. 36). It varies very much in size, and is generally 

 seen more prominently on the outside than on the inside, or vice 

 versa, and sometimes it is right through. Pressure on one side 

 makes it more apparent on the other. It seldom causes lameness, 

 but, being unsightly, is very objectionable, and is frequently asso- 

 ciated with large bog spavin. The treatment greatly resembles that 

 for windgall {par. 155). An indiarubber bandage may be applied, 

 or a truss specially prepared for the hock joint may be used, causing 

 compression and absorption. A winter's run at grass, with green 

 tar dressings of the affected part, have also been found to answer 

 splendidly. These bursal distensions, like windgall, bog" spavin, 

 and thorough pin, when very large, are sometimes tapped and 

 the oversecretion drawn off by means of a special instrument, an 

 aspirator ; but this should only be attempted by a professional 

 man, as it is very dangerous to admit air into a synovial or serous 

 cavity. 



158. Capped Hock consists of a swelling on and over the 

 point of the hock {Plate IX., No. 37), and is of two kinds, 

 either a serous or watery effusion immediately under the skin, or 

 a synovial or bursal distension. The serous capped hock is 

 caused by kicks or other bruises ; when recent, it is very painful to 

 the touch. Soothing treatment is necessary, such as hot or cold 

 applications, accompanied by cooling lotions {par. 1069, No. 1). All 



