You can't can you, because how could they fix it? Especially dog smell - dog owners don't notice it themselves anyway. (My MIL's house - uuuuurrrrrgggghh it stinks.)
There's also that weird "stale sweet biscuit" smell you get in some people's houses, but what causes it I have no idea.
Worst of all though, I have a friend who lives over a greasy spoon, and his flat reeks of stale cooking fat - blee. But I think he knows.