What were dog "breeds" like 500 years ago? I have read about the explosion of dog breeds in the 1800's (especially late 1800's), and have seen that most modern dog breeds are about 150 years old, though some are closer to 500 years old. In the 1500's or 1400's, were there different (fewer?) breeds, or where there just a handful of different types? And if you go back to the Middle Ages or Classical Antiquity, were dog breeds very different at all? Would we recognize them as similar to some of ours?
Mastiff type breeds, Rottweilers, bulldogs, boxers, and pit bulls are descendents of the Molosser, a breed developed in ancient Epirus in western Greece. The Romans made use of Molossers as war dogs, who had a built muscular frame with a powerful bite (modern Rottweilers have bites that can exceed 300 lbs per square inch in pressure).
The Jennings Dog is a famous Roman statue of a Molosser with a docked tail.
Chihuahuas and Mexican hairless dogs (the Xoloitzcuintli) have precolombian breed antecedents. I saw an Animal planet documentary that claimed the latter breed was used as "hot water bottles" for Aztecs during the winter.