How do you measure how popular a type of dog is if you intend to include mixed and unrecognized breeds? It is not an easy task.
You can look at the number of registered dogs at the large kennel clubs, but what about the unregistered dogs and mixed breeds? How do you count those dogs. I would estimate that there are just as many, if not more unregistered dogs than registered. Not all dogs have papers.
The Dog Breed Info Center® has had a classified ad section since 2003. This is a list showing the number of times a lister ran an ad under a particular dog breed category since the section was first launched. It gives everyone a general idea of how popular a type of dog is by showing how many ads have been listed under that type of dog in a 10 year period from 2003 to 2013. The numbers do not include want ads where people posted an ad looking for a type of dog.
Also Dog Breed Popularity Survey from September 7th 2013 to January 12th 2016