sudden aggression with my two boxers

Question
I have two female boxers, we rescued one 3 1/2 years ago, and we got a puppy last Oct. when she was six weeks old.
About 4 weeks ago the puppy became aggressive and keeps attacking the older one. Now I have to keep them seperated or they fight, they even freak out when they can see each other in theyre kennels, i don't want to get rid of the puppy, but i don't know what to do, she's crazy.

Answer
This didn't start overnight- it has progressed over time.

The "puppy" is at least 10 months old which is matured although, still a puppy, but coming into her own.

She is challenging the older female for the "alpha" position in the "pack" (two or more dogs plus family members is a pack).

Now, you will have to train them that you are the alpha- not either of them.

Begin with one- the youngest.

Sit her in front of you to watch you. Set her food bowl on the kitchen table or counter and fill it. Also, put cookies or crackers on the table or counter behind the dog food bowl.

Stand and eat the cookie or cracker, one by one, without looking at her.

When you are finished, place her bowl down in front of her and tell her "okay, eat."

In the wild, pack animals have an alpha, An alpha eats first, and eats all they want. When the alpha is finished, he or she will tell the other pack members they can eat if anything is left for them to eat. They do not eat unless the alpha tells them.

This will appear like you are eating from her dog food bowl. When you are finished, you tell her she can eat like the alpha does.

She will soon see you as the alpha.

Do this for 3 weeks daily, with each dog.

When you do have them in the same room together- leash the aggressor- the youngest, Do not allow her to attack or be aggressive to the older one.

At the first sign of aggression, push her down to the ground and hold her in the submissive position for 2 minutes minimum. Verbally reprimand her with easy-to-understand commands.

Continue the leash and control and reprimands until she begins to obey you on command.

Let me know how this goes in a few weeks to see if further steps should be taken.