2o8 THE SURGICAL ANATOMY OF THE HORSE 



surprising how rupture did not occur during the casting and struggling. 

 It contained a large amount of blood clot in various stages of organisation, 

 some portions being of quite recent origin. The right external iliac 

 artery was completely plugged with a firm thrombus of a pale yellow 

 colour, and the vessel was much smaller than normal, and felt like a firm 

 cord. The muscles of the off quarter were wasted to a marked degree 

 and very pale in colour. 



Remarks. — The similarity between some of the symptoms of azoturia 

 and those of the above case is a point worthy of attention. In such an 

 instance the history of the case is apt to lead to an erroneous diagnosis. 



This animal had been in her owner's possession for a period of twelve 

 years, and was never known to have anything amiss with her. The 

 coachman stated that of late years she appeared to show some weakness 

 of the hind limbs when going down a hill, but this he attributed to 

 the animal getting old. The owner stated that the above was pure 

 imagination. 



The case is thought interesting from many points of view, one of 

 which is that affections of this nature may be in existence without showing 

 any appreciable symptoms. Had this animal been cast and chloroformed 

 for any operation, it is very likely that she would have succumbed, and 

 unless a post-mortem were made the fatality would have been attributed 

 to the anjEsthetic. However, as events proved, she showed marked 

 resistance to the toxic effects of this agent. 



THE VEINS 



The digital veins, in their origin and relationships, resemble the 

 corresponding veins of the fore limb, and, like those of the latter, they 

 form a venous arch across the back of the limb just above the fetlock 

 and between the suspensory ligament and the perforans tendon. 



From this arch the blood is carried bv the three metatarsal veins. 



