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.
The Phu Quoc Ridgeback is a breed where the dogs are considered small.
In the context we do not know wheter the the Phu Quoc Ridgeback is small or not. However, the system may have  been confused by the statement that it is the smallest of the three Ridgeack breeds.  