It's a common question - what type of dog do you have? Or, more often than not, when it comes to the Lapdogs, it's "she looks like she's got some :::fill in the blank::: in her, but what else is she mixed with?"
With mixed breed rescue dogs, it's usually a best guess scenario depending on what they looks like. Pull up Petfinder and you'll be overwhelmed with "lab mixes," yet half of those dogs probably have zero Labrador in them.