LAMENESS IN THE REGION OF THE SHOULDER. 37 



about half an hour the lameuess disappears, to return when 

 again exposed to active work. 



InsiJection. — The animal is apparently all right when 

 standing still or walking, but becomes very lame if trotted 

 briskly for ten or fifteen minutes ; the lame leg begins to 

 tremble and can no longer support the weight of the body; 

 the animal stumbles and may fall. The horse may perspire 

 freely, yet the affected leg remains dry. When rested these 

 symptoms disappear, to reappear on active work. 



Palpation. — The lame leg, as a rule, is colder to the touch 

 than the sound one. 



DISEASE OF THE MUSCLES OF THE SHOULDER. 



History. — Lameness following falls, blows, stopping of the 

 horse suddenly while going at a fast gait, etc. 



Insjjection. — True swingiug-leg lameness, no pain being 

 evinced while the leg supports weight. More or less swelling 

 may be detected in one or the other muscle. 



Palpation. — Almost invariably swelling and heat can be 

 felt upon careful examination. One should bear in mind 

 that even animals not lame almost always flinch when strong 

 pressure is exerted on the shoulder, whereas in painful 

 lameuess sensation on pressure is not always expressed in a 

 like manner, as handling, liniments, blisters, etc., on the 

 actual or supposed seat of the lameness increase 

 sensitiveness. In recent cases pain is caused by pressing 

 upon or passively extending the affected muscles. Single 

 muscles, as the mastoido-humeralis, or whole groups, as the 

 pectoral muscles, when involved require careful palpation. 

 Drawing the leg backward is frequently painful. Atrophy 

 of the muscles of the shoulder occurs in cases of long- 

 standing, being particularly marked in the diseased muscles. 



