Mesenteric Vessel Rupture

Claire is happily reveling in her new status as “Teat Pea Queen” following the last case of the month. This time we have a new case from our newest team member Pete on Mesenteric Vessel Rupture. Unfortunately, in some investigations, a solution is not available…

I was called to post mortem a cow that had milk drop the night before and appeared unwell but had now been found dead the next morning.

She was blown up on her side having been moved to a more suitable location for a post mortem.

First incision made… WHOOSH. So much blood came pouring out of the hole! I continued making the hole bigger and more and more blood came out. Large blood clots were present throughout the abdomen.

Bleeding out into the abdomen is a rare cause of death in cattle. There are a number of causes including; abomasal ulcers, vessel rupture, ruptured uterine arteries and a selection of other more uncommon causes.

In this case, the abomasum was normal and no abnormalities were identifiable.

The Cause

The blood vessels supplying the guts are the mesenteric vessels; in this case the vessels which had ruptured seemed to be next to the third stomach, the omasum.

The cause of the vessel ruptures is unknown; the only paper that exists is an American study of Holsteins from 2007. This identified a weakness in the blood vessel wall. It seems to be genetic in nature, with cases of it being related to certain lines of cattle but not always, often presenting in single cases in single farms only. The APHA have published a letter which suggests that it is getting more common, but the reason is still unknown.

Strangely in this case, there have been four or five different well conditioned, Scandinavian cross cows that have died. The underlying cause in this case is likely genetic but it is very hard to prove. This is because there is unfortunately no test for the genes and no treatment as cows lose a tremendous amount of blood in very little time. Additionally, the clinical signs associated with it are vague.

A strange case and a frustrating one. No treatment or prevention is possible for animals with this condition at this current time!

Despite the unfortunate outcome in this case, a post mortem for animals that have died can be invaluable for learning about disease; congenital or otherwise that may be present on your farm. If you do not want a post mortem on farm, we can also meet the carcase at a knacker yard.

A legal note. Any sudden, unexplained deaths in cattle should be reported to APHA as an Anthrax enquiry may be required.