DISEASES OF THE HORSE. 341 



trunk, may not be of serious import and may readily yield to treat- 

 ment, or even recover spontaneously and without interference, the 

 condition is quite changed when a case of tearing of the flexor brachii, 

 or of its tendons as they pass in front of the articulation, occurs, or, 

 what is still more serious, if there is inflammation or ulceration in the 

 groove over which this tendon slides, or upon the articular surfaces or 

 their surroundings, or periostitis at any point adjacent. 



Causes. — The frequency of attacks of shoulder lameness is not diffi- 

 cult to account for. The superficial and unprotected position of the 

 part, and the numerous movements of which it is capable, and which 

 in fact it performs, render it both subjectively and objectively preemi- 

 nently liable to accident or injury. It would be difficult, nor would 

 it materiall}' avail, to enumerate all the forms of violence by which 

 the shoulder may be crippled. A fall, accompanied by powerful con- 

 cussion; a violent muscular contraction in starting a heavily loaded 

 vehicle from a standstill; a misstep following a quick muscular effort; 

 a jump accompanied b}' miscalculated results in alighting; a slip on a 

 smooth, icy road; balling the feet with snow; colliding with another 

 horse or other object — indeed, the list might be indefinitely extended, 

 but it would be without profit or utility. 



Symptoms. — Some of the S3miptoms of shoulder lameness are pecu- 

 liar to themselves, and yet the trouble is frequently mistaken for 

 other affections — navicular disease more often than any other. The 

 fact that in both affections there are instances when the external 

 symptoms are but imperfectly defined, and that one of them especially 

 is very similar in both, is sufficient to mislead careless or inexperi- 

 enced observers, and to occasion the error which is sometimes com- 

 mitted of applying to one disease the name of the other, erring both 

 ways in the interchange. The true designation of pathological lesions 

 is very far, at times, from being of certain and easy accomplishment, 

 and, owing to the massive structure of the parts we are considering, this 

 is especially true in the present connection. And still there are many 

 cases in which there is really no reasonable excuse for an error in 

 diagnosis by an average practitioner. 



Shoulder lameness Vv^ill of course manifest itself b}^ signs and 

 appearances more or less distinct and pronounced, according to the 

 nature of the degree and the extent of the originating cause. We 

 summarize some of these signs and appearances: 



The lameness is not intermittent but continued, the disturbance of 

 motion gauging the severity of the lesion and its extent. It is more 

 marked when the bones are diseased than when the muscles alone are 

 affected. When in motion the two upper bony levers — the shoulder 

 blade and the bone of the upper arm— are reduced to nearly complete 

 immobility and the walking is performed by the complete displace- 

 ment of the entire mass, which is dragged forward without either 



