522 
SHOULDER LAMENESS. 
membrane was thickened and covered with numerous thread-like prolifera¬ 
tions, and the articular surface of the scapula increased to the extent of about 
an inch by a circular bony growth. The cartilage covering the articular 
surfaces, both of the scapula and humerus, was abraded. 
(2) Disease of the muscular tissues of the shoulder is sometimes 
traumatic, sometimes rheumatic, in origin. External violence, or violent 
falls or leaps, may produce inflammation of the shoulder muscles. 
Gerlach erroneously assigned these conditions to the biceps; hut although 
we are not in a position to absolutely deny their occurrence in this 
position, yet they are exceedingly rare. Nesbit reported a case in which 
both biceps brachii muscles were torn away from the coracoid process 
(see “ Inflammation of the Bursa of the Biceps Muscle ”)• Inflammatory 
symptoms, such as increased warmth, pain on pressure, or on extending 
the diseased muscles, can almost always be detected on careful examina¬ 
tion, but care and judgment are required in order to avoid error. 
Most horses flinch under strong pressure on the shoulder, nor is 
tenderness a constant symptom even in painful lamenesses, so that it 
is quite erroneous to consider that it is simply a question of unequal 
sensitiveness. Moreover, the affected spot has often been made more 
sensitive by manipulation, or by the application of irritants. On the 
other hand, inflammation occurs in single muscles, like the levator 
humeri, and even in entire muscular groups, such as the pectoral 
muscles, in consequence of bruises and sprains, and in young horses 
from severe exertion, and can only be detected by careful palpation. On 
drawing the foot backwards, the animals show pain. 
These conditions are usually accompanied by lameness while the limb 
is being advanced, though none is shown when weight is placed on it. 
After some time muscular atrophy sets in, and is most marked in the 
region of the diseased muscles. 
Rheumatic disease of the shoulder muscles, which is especially common 
in the levator humeri, produces similar symptoms. Pain generally 
diminishes during movement, and may entirely disappear when the 
animal begins to sweat. Rheumatic disease is indicated by remittent 
or intermittent lameness, and by unusual pain after slight sudden move¬ 
ment of the muscles, such as that produced by flipping the parts with 
the finger, whilst powerful pressure is less painful. Sometimes extensive 
contraction can be induced in single muscles, e.g., in the entire levator 
humeri, by a light blow with the finger. In disease of this character in 
the levator humeri, the animal’s neck is drawn downwards and towards 
the diseased side (torticollis), and the muscle appears very tense and 
prominent. 
Piitz saw a peculiar shoulder lameness : movement was difficult, though 
the animal showed no pain on examination. The muscles were swollen but 
