DISEASES OP AETEBIES 269 



The ruptures of which larger arteries and veins are of clinical 

 interest ? 



The seat of predilection of the aorta is at the aortic sinus. 

 As previously stated, blood pressure is excessive here, there 

 is naturally some dilatation, the walls are somewhat thin. In 

 ■cases of rupture at this point, the blood empties into the peri- 

 <5ardium. The more common causes are : throwing an animal 

 for an operation, fast running and jumping, wagon poles 

 entering the thorax. Rupture of the pulmonary artery, the 

 result of throwing the creature, has also been observed ; rup- 

 ture of the obturator artery sometimes follows pelvic frac- 

 tures ; rupture of the anterior mesenteric artery, especially 

 when affected with an aneurism, has been known to follow 

 the throwing of a horse. Of the veins, the vena cava and por- 

 tal vein occasionally rupture. 



What a/re the symptoms of rv/ptwre of the larger arteries and 

 veins f 

 Mucous membranes very pale, extremities cold, breath 

 «old, pulse very weak and soon beyond detection; the animal 

 «ways and falls ; occasionally convulsions. 



OvMine the treatment of ruptwre of an artery ? 



Whenever possible, the bleeding vessel should be ligated, 

 lut in the majority of cases the animal will bleed to death, as 

 the vessels are beyond reach- 



