DISEASES OF THE ARTERIES AND VEINS 475 



After a short period of rest the symptoms subside, and the horse resumes 

 his normal condition, and will most likely continue in apparent good health 

 until the exertion is again repeated. Although the symptoms described 

 are very indicative of iliac thrombosis, the diagnosis may be rendered still 

 more complete by a careful manipulation of the affected vessels. In this 

 connection it will be remembered that the iliac arteries are to be found 

 striking off right and left beneath the lumbar spine, and quite within 

 reach of the hand when pushed well forward into the rectum. In carrying 

 out this examination the hand and arm must be well anointed with oil 

 or vaseline, and after entering the bowel the arm is turned so that the 

 palm is presented upward ; the fingers are then directed to that part of the 

 spine where the loin joins on to the quarters, immediately beneath which 

 the great iliac vessels — two on either side — will be felt branching oft' right 

 and left from the posterior aorta. 



When healthy, they are found to pulsate forcibly with each beat of 

 the heart, and to be distinctly compressible, though always tense. When, 

 however, they are filled with coagulated blood and rendered solid, as in 

 this disease, the pulsation is no longer felt, and the vessels become hard 

 and unyielding. If they are not completely blocked a slight pulsation 

 may be felt, as a thin stream of blood passes over the clot, but the aftected 

 vessels in any case will have lost their pliancy, and will offer very decided 

 resistance to deep pressure. 



Treatment in these cases is of no avail. The fibrinous matter plastered 

 over the inner surface of the vessel in successive layers, or free within it 

 and occluding the passage of the blood, cannot be removed, and the animal 

 should therefore be destroyed. 



THROMBOSIS OF THE JUGULAR VEIN (PHLEBITIS) 



As already noticed, thrombosis of the jugular vein was a disease of 

 common occurrence in the days of indiscriminate blood-letting and unclean 

 surgical practice as pursued before the advent of antiseptic surgery when 

 phlebitis frequently followed the operation. In more recent years, since 

 the lancet and the fieam have been laid aside, it has become a rare and 

 exceptional ailment. 



As in arteries, so in veins, thrombosis is the result of degeneration or 

 injury inflicted on the wall of the vessel. It also results when the vessels 

 become varicose or abnormally dilated. In the particular instance under 

 consideration it follows upon the operation of bleeding, or the accidental 

 opening of the jugular vein. But the immediate cause is not perhaps 

 the injury alone, but the introduction into the wound at the time, or 



