Boxer bitch aggression

Question
I have two boxers, a 4 year old male & a 3 year old DEAF bitch. They have the same parents and absolutely love each other except around food, possessions and being greeted first. The bitch is really mean to the dog and will tear into him on these occasions.
They are walked twice daily, an hour each time and are extremely chilled for boxers. She has always pulled on the lead and has to wear a halti but still has to be in the front! Her aggression has increased to other dogs since she saw the male attacked by a retriever a couple of years ago and now she will attack most dogs, however she loves greyhounds and becomes quite submissive around them.
Over the last few weeks her aggression has increased and if she cannot get yo the fog she will nip whatever/whoever is in her way.
I have ordered a Baskerville muzzle, advise from my vet, but I am very worried about her. Please could you offer some advise?

Answer
First, she is deaf. That is one problem. She cannot hear the sounds of other dogs to know their intentions, etc.

She has an aggressive nature as a defense due to her handicap.

This is normal.

Being food aggressive is easy to fix.

Try this for a month:

Stand at a kitchen counter or table with her food bowl with food, sitting on the counter/table.

Stand there and eat a cookie or cracker. Take your time. Do not look at her while eating.

After eating, set her food bowl down in front of her. Do not allow her to have it until you give her the "okay" command to eat.

This establishes that you are the alpha and eat first as in nature with wolves, etc.

After the alpha eats what he wants, he allows the pack to have the remainder of the kill, to eat.

Do this with both dogs.

I hope you know canine sign language. If not, Google it and you will find good examples of this to learn and teach her.

The possession aggression is simple as well.

Try this:

Take all toys and possessions away from both dogs.

Buy a new toy for each dog that is alike; maybe different color or if not offered, then exact. They will go off smell to identify.

Give each dog their new toy. Only one toy for a week or so.

If there is any aggression, stop her. This is when sign language is necessary. You need to learn it if you haven't already.

Take the toys away if there is aggression. They will soon associate bad behavior/aggression, means no toy.

When greeting them, try greeting them both with a special treat then pet each at the same time keeping them from jumping up on you, etc. Good behavior should be rewarded.

Let me know how this goes for you in a follow-up later, please.