agression toward new puppy

Question
We recently adopted a 8wk old male puppy. Our male boxer who has shown no aggression ever is now showing aggression whenever the puppy is being given a "treat". He has snatched him up and have to fight him to let go. We are supervising @ all times. it is almost as if our boxer is watching us and knows when we turn our backs, as he is doing this w/ us present in the same room. We have been giving extra food and treats to ensure him that we have not forgotten him, also make sure to pet him while we are holding pup. He is not yet nuetered will this make a difference? Not sure what to do, we have 4 young children and he has never been aggresive toward our kids! But I am worried!!!!!! Do not want to part w either of them.  I have always owned boxers and never dealt w this, hence why we chose to continue w/ this breed once we had children! This is upsetting our entire family dynamic. Please help us!!!

Answer
A male Boxer that has always been the only dog in the family feels he is the alpha of the family (you didn't mention his age).

A male knows that another male (puppy) will grow up to challenge the alpha position. This is why in the wild, males will kill male offspring (pups).

If you had gotten a female puppy, it might have been different.

Since you have a male puppy and this problem, it will take time and patience.

Use a whistle or blow an air horn when he becomes aggressive. Startle him with the sound and to teach him it means bad behavior. He will stop- then you must reprimand him by removing him and crate him in a time-out.

Over time, he will learn that he will be punished.

In the meantime, supervise them together, have the whistle or air horn handy, and a leash handy. Blow the whistle or air horn, leash him and verbally reprimand him and crate him in a time-out.