What smell does street dogs hate the most?

I'm not sure if you can actually offend a dog, but we used to have a Staffordshire Bull Terrier who lapsed into uncontrollable sneezing when encountering perfumes - of the sort used by women and some men and of the type used in air fresheners, detergents and the like. She also disliked petroleum vapours, so I tend to think this would probably be the effect of the carrier rather than the smell itself, particularly since the same dog used to sniff flowers!