We are not sure what she is a mix of, but she’s not as big as the ridgeback the guy up the street had. Similar look though and yes has a ridge, can see it when her hackles are raised. 75lb right now, and the vet says that’s 5lb over, so she isn’t huge, just on the big side of medium. Vet has her listed as lab/shepherd mix but we don’t know, at all.