How can i get this dog to stop?

Ok like i have a dog he is 8 months and my uncle has a Miniature Schnauzer and like my uncles dog will bite my dog and hold on and my dog will drag him and try to get him off and my uncle and his kids thinks its funny but when my dog even attempts to get the dog to stop they get mad because my dog is so big like my dog could bite my uncles head off with no problem so how can i get there dog to stop? my dog has never like retaliated violently really he just puts his paws on the small dog so it cant get up but i don't want my dog to react badly and hurt there dog then my dog will be in trouble even though there dog has been biting my dog and has made him bleed a couple of times.