Premise: The Phu Quoc Ridgeback is a breed of dog from Phú Quốc Island in Vietnam's southern Kiên Giang Province. The Phu Quoc Ridgeback is one of only three breeds that has a ridge of hair that runs along its back in the opposite direction from the rest of the coat (the others are Rhodesian Ridgeback and Thai Ridgeback). The Phu Quoc is the smallest of the three ridgeback breeds.
Hypothesis: The Thai Ridgeback is a crossbreed of the Phu Quoc Ridgeback