Rodent droppings scattered all over the attic- Dealbreaker?

[Rob C.]

A house I'm considering purchasing has a pest problem, and there are a lot of rodent droppings in the garage and attic. If I go through with purchasing it, I'm planning to hire a pest control company to get rid of the pests. But what about the droppings they've already left behind? I imagine it would be rather costly to clean the droppings scattered about the insulation throughout the attic. Is this a health hazard? Do they make a house legally uninhabitable? And do average homeowners (i.e. not investors) consider this a dealbreaker when looking to buy a house?

Thanks, Rob