I voted Medium and Small, but it depends where you put the line lol

Happy, Misty and Electra are all Medium none more then 35lbs at proper weight(21", 18" and 17" respectivly)

Perky, Ripley and Rusty however.. Rusty is 15" tall, but he's only 15lbs. Ripley and Perky are 13" and 12" tall and 18lbs and 22lbs respectivly. so techinicall they could fall into small or medium depending on how you want to measure it and where your draw the lines lol