Raw bones how long outside?

[Notonaschoolnight]

Pup's as happy as a pig in poo right now chewing on bone in the garden but what are the rules for this in terms of germs/bacteria.

I only let mine have them for the one day, I don't know about bacteria and germs but my theory is if its been outside its not coming in my house and you can't tell if any slugs / snails have crawled on it and I worry about lungworms ( even though I worm for them )