116 THE EXTERIOR OF THE HORSE. 



anatomical region coexists with that of the others, whatever may be 

 their number. With respect to the horse, however, it is necessary to 

 guard ourselves against such an absolute generalization ; it is essential 

 to remember that the shoulder or the thorax can p-ive this region a 

 prominence in which the withers do not really assume that importance 

 which might be supposed from a point of view of the exterior. Such, 

 at least, have been the deductions made from our own observations. 



Diseases and. Blemishes. — The withers, in consequence of their promi- 

 nence, situation, and anatomical c()m})lexity, are exposed to numerous lesions of 

 variable gravity. Blows, chaiing, bruises, and bites are among the causes which 

 may lead to swellings, wounds, or abscesses with profound complications of 

 necrosis and caries of the bones, the muscles, and the ligaments. These affec- 

 tions, known under the generic name of evils of the wifhers, render themselves 

 apparent, in the majority of instances, by an extraordinary exaggeration of the 

 sensibility, abnormal enlargement of the part, cicatrices, or fistulous tracts dis- 

 charging pus, which leave their evidence by soiling and decorticating the adja- 

 cent skin. 



Horses in such a condition are not rarely offered for sale, and we know of 

 two instances in which the dealer cleverly concealed the tumefaction and the 

 fistula, of which it was the seat, with a blanket. 



It is more common to meet animals which offer accidental white markings 

 or cicatrices more or less large, where the skin is denuded, thin, and more easily 

 excoriated by the contact of the harness. The presence of these cicatrices 

 furnishes, besides, the evidence of a pre-existing disease implicating the muscles 

 or the bones of the withers and the shoulder, which may result in some irregu- 

 larity of the gait. They have an important bearing in an examination for 

 soundness in the purchase of horses. 



Other blemishes may also result from the application of blisters or the actual 

 cautery. They have their principal value, however, when the affection for the 

 cure of which they have been applied has not yet disappeared. Such diseases are 

 liable to return or become augmented under the persistent action of the causes 

 which produced them. 



3. The freedom from blemishes, in a general way, as related 

 to the physiological appearance, is, therefore, as indispensable to our 

 study as the form, the elevation, or the extent. 



C— The Back. 

 Situation ; Limits ; Anatomical Base. — This single region, 

 situated on the superior part of the trunk, is limited anteriorly by the 

 withers, posteriorly by the loins, and laterally by the ribs (sides). 



It has for its osseous base the eleven or twelve posterior dorsal vertebrae and 

 the superior extremity of the corresponding ribs. These bones give attachment 

 to the different muscles which fill the costo-vertebral grooves, — the great dorsal, 

 the small anterior and posterior serrated, the ilio-spinalis, the transverse spinous, 

 and the intercostals. 



