This would be a fairly rare presentation of a hemangiosarcome,
so there may not be anyone else who can tell you how their dog's
case turned out.
Hemangiosarcoma is an invasive tumor that arises from the cells
lining blood vessels. The most common sites are in the spleen and
around the base of the heart. Treatment generally consists of
attempting to remove as much of the tumor as possible, which is
great if the tumor is localized to just the thigh. Dogs tend to do
pretty well with only three legs - you can ask anyone who has
worked with rescued racing greyhounds about this.
The bad part about hemangiosarcomas is that they try to make new
blood vessels branching off of the existing cardiovascular system.
The new blood vessels are very weak, and can rupture at any time.
If the tumor is not removed, your dog may live anywhere between
another few minutes and another few years - but every time you
leave the house you risk coming back and seeing that your dog has
died from the weak tumor blood vessels rupturing. Running, jumping
and playing would increase this risk, as blood pressure would
increase and you would have increased mechanical stress on the
vessels as well.
German Shepherds and Gold Retrievers appear to have a higher
risk of developing hemangiosarcomas. The tragic part about this
type of cancer is the first symptom is generally "I left for work
and he was fine, I came back home and he was dead". The death is
very rapid due to bleeding out internally.
