In a recent study in the journal Animal Behaviour, Heberlein and Turner found that dogs were more likely to search for food after observing another dog foraging if they smelled food on the other dog’s breath. After the first dog searched for food, the two dogs made snout-to-snout contact. If the first dog had successfully found food, then the second dog was more willing to seek food from the experimental set up.
The ability to find food based on what other members of the social group have located is common in many species, including insects, birds and mammals. It is no surprise that dogs, being such a highly social species, rely at least partially on other dogs to help them locate food. And it makes sense that since dog breath is so strong, that it is also useful.