Dogs who roll in shit are... covered in shit. That is how you know @GasPanic
Most dogs don't eat harmful shit, ie carnivore shit, the exception being cat shit and thats because humans feed cats a piss poor diet that leaves a lot of undigested protein in the crap. They mostly eat herbivore shit which is a natural part of a scavengers diet and where they get beneficial bacteria... however they can only do this if they have access to it.
Mine eat zero shit, they have no access to cat shit or herbivore shit.
They will on occasion roll in a fox shit, this is evident because:
- they stink like fox crap
- they have fox crap on them
If this occurs, they get a bath. Or three.
They don't pick up fleas and ticks because I use preventative collars and treat the house for fleas regularly.
They do shed hair and skin.So do I. I remove this by vacuuming and washing bedding.
Piss/crap/vomit - again yes they do do those things, so do I. We all attempt to do them in the correct places, which is not in my bed/on my floors.
SO no they're not 100% hygenic, sterile, crud free. But they're not significantly more disgusting than humans either.