478 WOUNDS OF THE CHEST-WALL. 



drainage. If not, free exit for discharge must be provided. Dis- 

 infectant injections should be tried, and the wound kept clean. Where 

 possible, the diseased bone should be scraped with the curette. For 

 this purpose it will often be necessary to cast the animal. The actual 

 cautery under certain circumstances may be useful, but it must 

 be carefully employed, or the disease may be aggravated. 



Fracture of the sternum, which is rare in horses, was observed 

 by Sand. The horse had run away and fallen violently to the ground. 

 It rose, however, and after galloping a further distance of about 

 400 yards suddenly fell once more, and immediately died. Death 

 was found to have been due to injury to the internal thoracic artery, 

 which had been torn by a fragment of the sternum. Sand thinks 

 that the horse had fallen on its shoe. 



IV.- WOUNDS AND BRUISES OF THE SOFT PARTS OF THE 

 CHEST-WALL. 



(1.) WOUNDS OF THE CHEST-WALL WITHOUT 

 PERFORATION. 



Wounds associated with injury of the sternum have already 

 been discussed, and consideration has now to be given to those of 

 the soft parts ; injuries due to collar pressure will be considered 

 elsewhere. Such wounds in horses are caused by collisions with 

 the pole of the carriage, by two animals meeting violently ; in the 

 army by lance thrusts, or by falling on uneven hard ground or on 

 the rider's spur. When the injury is on the anterior surface of the 

 chest, the trachea, the great vessels, and the first ribs may be 

 endangered. Injuries to the sides may consist of extensive gashes 

 in the chest and shoulder muscles, or an offending body may force 

 its way between chest-wall and shoulder, severely damaging the larger 

 blood-vessels and nerves. 



Thienemann records that a horse, which had received a wound 

 over the elbow and died two days afterwards, had the axillary vein 

 torn through. Hiibner describes a case in which the horse fell ; 

 a fluctuating swelling immediately appeared, in consequence of rupture 

 of the axillary artery, gradually extended over the neck and chest, 

 and proved fatal forty-five minutes later. 



Prognosis depends chiefly on the position and degree of the injury. 

 Wounds involving only the skin and superficial layer of muscle usually 

 heal well, especially if the discharge finds ready exit ; but deep- 

 penetrating wounds of the lower border of the neck are very grave ; 



