3 The pug/beagle/shar-pei, the beagle, and the pug/beagle.
2 or 3
About 300. But it is ever increasing, by the owners breeding cross dogs, etc. If you take the spaniel group for instance,they have many different types, which can include: Clumber spaniels Cocker...
about over 200 dog breeds
One. The names you hear or read are the bloodlines within the breed.
there are over 500 different breeds