ANEURISMS, 333 
smallest like the scratch of a nail, having sharp, ragged and sinuous 
edges ; it occupied the entire thickness of the wall; its bottom seemed 
formed by a fine transparent anhistous membrane. ‘The other, situated 
like the preceding on the dorsal face of the vessel, presented the saine 
external characters; the tear started from its bottom. 
Rupture of the pulmonary artery, primitive aorta or one of its divisions, 
ordinarily kills in a few minutes; all attempt at interference is useless. 
With those of secondary and superficial arterial trunks, treatment may 
be efficacious. Pressure on the vessel, on the cardiac end, may sometimes 
arrest the hemorrhage, specially if with it cold effusions and astringents 
are used. The application of a compressive bandage may also give good 
results. If, notwithstanding these, the blood continues to accumulate 
under the skin, the ends of the ruptured vessel must be looked for and. 
secured with ligature. 
To rupture of blood vessels can be added the perforation of their coats 
by nemathelmintes which they may,contain. This accident has been 
observed in horses with the sclerostomus armatus (Durieux) and in the 
‘dog by the sanguineous spiropterus (Morgagni, Degive, Megnin.)’ 
III. 
ANEURISMS. 
According to the form of the arterial dilatation, aneurisms are divided 
into fusiform, when they occupy the whole diameter of the vessel, and. 
sacciform, when limited to a portion of the wall only. Their origin is 
primitive or spontaneous. A bruise may divide the internal membranes 
of an artery and create a locus minoris resistensig, where the traumatic 
aneurism takes place. Acute or chronic inflammation of blood vessels, 
atheroma, promote the formation of spontaneous aneurisms. Endarte- 
ritis is often due to parasites (strongyli, spiroptera). In the majority of 
horses, the great mesenteric, and at times the small and the celiac axis 
are the seat of aneurismal lesions due to the stvongylus armatus. Very 
severe colics (intestinal congestion, thrombo-embolic colics) seem to be the 
result of an infection starting from these points. Megnin has described in 
the dog two cases of aneurisms of the aorta due to the sanguinolenta 
Spiroplera. 
1 A case of rupture of the internal iliac is reported by W. J. Martin occurring in a 
mare during the manipulations made by the owner to relieve her in a case of distokia. 
The mare had received a small dose of chleroform to quiet her pains but died as her 
_ colt was removed.. At the postmortem the rupture of the artery was found just below 
the junction where it leaves the posterior aorta——American Vet. Review, vol. xxiii, 
page 114. 
