Shoulder Lameness.

This enigmatical term is frequently employed by the diagnostician when he is baffled in the matter of definitely locating the cause of lameness; when he has by exclusion and otherwise arrived at a decision that lameness is “high up.”  Shoulder lameness may be caused by any one or several of a number of conditions, e.g., fractures of the scapula or humerus; arthritis of the shoulder or elbow joint; luxation of the shoulder or elbow joint (rarely); injuries of muscles and tendons of the region due to strains, contusions or penetrant wounds; paralysis of the brachial plexus or of the prescapular nerve; involvement of lymph glands; arterial thrombosis; metastatic infections; rheumatic disturbances; and as the result of inflammation, infectious or non-infectious occasioned by collar bruises.  In some instances such inflammation is due to the manner of treatment of collar injuries.  Therefore, when one considers the numerous and dissimilar possible causes of shoulder lameness, it behooves the practitioner to become proficient in diagnostic principles.

A principle which is elemental in the diagnosis of locomotory impediment, is that lameness of the shoulder or hip is usually manifested by more or less difficulty in swinging the affected member.  Swinging-leg-lameness, then, is usually present in shoulder affections.  In some instances lameness is mixed as in joint ailments, involvement of the bicipital bursa (bursa intertubercularis), etc.  In affections of the extremity there exists supporting leg lameness.  Consequently, we employ this elemental principle, and, by a visual examination of the subject, which is being made to travel suitably, one may decide that lameness is either “high up”—­shoulder lameness or, “low down”—­of the extremity.

[Illustration:  Fig. 5—­Ordinary type of heavy sling.]

To make practical use of this principle, the examiner must be thoroughly familiar with the anatomy of the various structures concerned in advancing the leg—­those which support weight as well as those concerned both in weight bearing and swinging the member.

Fracture of the Scapula.

Etiology and Occurrence.—­Fractures of the body of the scapula are of infrequent occurrence in horses for the reason that protection is afforded this bone because of its position.  Its function, too, is such that very unusual conditions are necessary to subject it to fracture.  The spine is occasionally broken due to blows such as kicks, etc., and here frequently a compound fracture exists.

[Illustration:  Fig. 6—­A sling made in two parts so that horses may be supported without use of central part or bodice.  This sling is more comfortable than is the ordinary style and is particularly useful in cases that require a long period of this manner of confinement.]

Where fractures of the body of the scapula occur, heavy contusions have been the cause as a rule, and serious injury is done the subject; consequently, treatment of fracture of the body of the scapula is seldom successfully practised.  Fractures of the body of this bone resulting from accidents not involving internal injury or other disturbances and which would not seriously interfere with the vitality of the subject, are not necessarily serious unless compound.