A feist is a small terrier. It is said that all rat terriers are feists but not all feists are rat terriers. Some of the breeds that went into the feists are fox terriers, white terriers, black and tan terriers, beagle, whippet and even chihuahua in some lines.
Generally our feists are seperated from the cur breeds by weight class with the curs being larger and similar in make up though often with more bully breed and hound influences.