Can dogs eat dairy foods i.e. cheese cream yogurt - given they wouldn't get these in the wild - or will it make them sick?

Yes, but it should be given them in small quantities as it may constipate them as it does humans. It can effectively be used to coax down medicine, or as a treat/ treat ingredient. Dairy consumption also can encourage excess mucous production- another reason to be sparing. and for yogurt it is very good if the dog is have throw-up problems.