[quote=@Horrid]
[@knighthawk] Hell hounds are classed in D&D, as Outsiders. Dealing with their blood in the first place, as a good-aligned character, is a bad move. Its like handling radioactive waste. MAGIC radioactive waste. SOUL waste.

We don't have the proper protection to be handling contaminants of this sort. But oh well, now we've got bad blood.
[/quote]

Well, outsiders don't leave a body to extract blood in the first place if we're going by D&D rules. Their body dissolves into whatever essence comprises their bodies, usually positive, or in a hellhound's case negative.