CASE OF PARTIAL OCCLUSION OF THE TRACHEA. 189 
lary vessels of the mucous membrane of the bladder, and the 
horse being aged, it was recommended that he should be 
destroyed. 
On the 12th instant he was destroyed, and & post-mortem 
examination made ; and when the slaughterman removed the 
intestines we perceived an enlarged condition of the posterior 
aorta, a little behind the anterior mesenteric artery. The 
kidneys were detached, and upon examination were found to 
be normal. The bladder was distended with a large quantity 
of fluid. A ligature was passed round its neck, and it was 
carefully removed. Upon cutting into it there was found a 
giving way of some of the capillary vessels of the mucous 
lining membrane, causing slight haemorrhage, which was in- 
dicated by numerous petechiee. This, no doubt, was the 
cause of the existence of blood in the urine. 
The aneurismal sac was eleven inches in circumference at 
the largest part ; the walls of the cavity were attenuated, but 
the loss of thickness was in some degree compensated by cal- 
careous deposit, which must have materially added to the 
insistent power of the structure. There were no traces of the 
parasites (strongyles) which are so commonly found in con- 
nection with dilatation of arterial trunks in the lower 
animals, the horse and ass especially ; it is, however, quite 
probable that they were present at the commencement of 
the disease. 
OBSERVATIONS ON MR. OVERED’S CASE OF 
PARTIAL OCCLUSION OF THE TRACHEA. 
By Alfred Owles, M.R.C.V.S., 6th Dragoons. 
The case of partial occlusion of the trachea which was 
recorded in your Journal for the past month by Mr. Overed 
appears to possess some points of special interest with refer- 
ence to the amount of dyspnoea which was present at times, 
and, as reported, the almost perfect freedom from difficulty 
in the animaFs breathing at other times. 
Is it assumed that the mechanical obstruction arising from 
the deposit in the trachea, which lessened its calibre, was the 
direct cause of the extreme difficulty in breathing. If so, 
does such an hypothesis account for the fact that at other 
times there was* little, if any, difficulty of breathing present, 
although the mechanical obstruction arising from the deposit 
xliii. 14 
