We purchased a Great Pyrenees/ lab mix (Harlee) about 3 months ago... she is now 5 months old. A few days ago we purchased a boxer/ lab mix (Biscuit) who is almost 3 months old. Harlee weighs 50 lbs and is huge for her age. Biscuit is maybe 6 or 7 lbs and is tiny. When they play, Harlee pounces on her and bites too hard which causes Biscuit to yelp. She is too rough with the little pup. We have tried EVERYTHING, including separating them and putting Harlee in her kennel. She doesn’t care, and continues to play too rough with Biscuit. I’m at my wits end. What Can I do to make Harlee be more gentle with the new pup?
I would completely separate them. You can’t risk your bigger puppy harming the smaller one. When I got my puppy, she was kept separate from my two older dogs for over two months until they got used to one another, and to allow the puppy to grow up a bit. It sounds like you may need to do the same. Using a puppy pen and baby gates it is easy enough to keep them apart except when you are able to micro-manage their interactions by sitting on the floor between them. It will get better in time, but until then, you need to keep your little one safe.
I agree with @snowbunny - some pups are just too rough together. When Twiglet’s brother, Rossi, used to visit we couldn’t let them play - she was so rough with him it was dangerous .