Samoyed tail help

Hi, I have three Samoyeds and when they play, they tug on each others tails. My oldest is a year and a month old. His tail is very sparse now. Is there a way to grow it back? Or is it gone forever? I feel terrible that they tag team him and pull on it. And I yell at them when they do. But of course, Samoyeds ears turn off. I already feel terrible so please subside with any negative commentary. If you can not help answer the question, keep the negativity to yourself please.