I am going to go out on a limb here but this is just my opinion and each person has to decide what is right for themselves. In this case I think it is best for you to rehome your bigger pup. Guilt is never a reason to keep a dog and your big guy will probably always be a problem to your little ones. I really think in the best interest of the
dog you either find a home where he will be loved for himself and size is not an issue or you turn him over to a reputable rescue which will find the perfect home for him. I know people are having problems with this issue and I can understand why but I think you have to think of this pup who will always be in trouble with you and can't be a puppy and do the things puppies do. I really do think this is the kindness thing you can do for this pup. In rescue many young pups (5/6 months old) have come through (due to different situtations but mainly due to potty training or no time for the dog or issues with other dogs) and in some cases the people really did love their dog but realized the kindest thing they could do was turn them over to rescue. I appreciated people being honest because during many of the interviews with these people they always would say we were going to give them up, people made us feel guilty and it just progresssively got worst. In the long run more harm (not abuse for the most part) was done to the pup or they spent to much time in kennels.
