jugular vein scarring:

[Douglas M Gifford <dpwg@juno.com>]

I remember when we  were discussing
the pros and cons  of jugging a horse to get fluids into him.
Well on Fri night I got a first hand look at a horse that
has scarring in the jugular vein due to a shot given IV
of Bute. The horse had nice  huge varicosities around his
eye and every time he would lower his head to eat they got 50%
bigger. The vet had ultra sounded this horse and said he was
not completely blocked but recommended that the owner give
bute grains to help keep the inflamation down in the jugular.
Meanwhile the horse is establishing collateral veins to help with
circulation. I got a first hand look at what you were talking about and
boy was I impressed by this horses situation and the knowlege that
ridecamp has to offer on lots of different things.
Pat and Razzel (never stop learning or you may as well be dead)