Personally, I voted for large because I've got 3 with all different sizes right now. Destiny, the dalmation is considered to be a medium sized dog. Dakota, the great dane, I consider to be an extra large sized dog because that's what danes seem to be considered, yet she's a puppy too. Sierra, the lab mix however, would probably fit in the small right now because she's not quite 3 months and just a small puppy at this point. So, if you average them all out, I think you'd get a large breed dog (that's truly how big Dakota is getting at this point)!