Two things:
1) Sometimes those determined chain-fighters are determined in other areas as well ... more often than you might think ... for if they have the intelligence to know that "the chain" is what is confining them ... and relentlessly attack it ... they often have intelligence and are unrelenting in other areas as well
and
2) Wouldn't a much more compassionate/intelligent solution for such a problem dog be placing it in an above-ground pen as opposed to executing it?
Jack