Loving male Chihuahua in tact (Amarillo,tx)

It is with a heavy heart that I am doing this.
TJ is in need of a new home.
Our female Heeler has become very aggressive with him.
We have tried discipline and separation of the 2 to no success.
I am afraid she will seriously hurt him.
I know rehoming her with her aggression would never happen so my little man is the one to go for his safety.
I found him as a puppy in a dumpster on the East side and have had him for 4 years without any problems.
I’m going to say he is around 4.
5 years old.
There is no rehoming fee, but only to the right people.
I will want to see his new home.