Originally Posted by Chiefnj2
It would seem to me that cutting off someones leg would increase the risk that they bleed out.
I didn't see the amputation as a means to stop the bleeding. Anyone that is bitten isn't killed by the virus they are killed by the fever that follows a bite from a walker.
Just like a bite from a human, I am assuming that there are all kinds of bacteria in a walkers mouth. When bitten (much like human bites), it causes infection, which causes a fever.
They cut off the source of infection and fever to keep Hershel alive. Then tied him up in the event he died from blood loss and turned.