Oh OP this is heartbreaking and I am so sorry for everything you have been through. The time has come, as other posters have said, for this to stop.
Regardless of what your son has witnessed or experienced, this is abhorrent and, with his actions, he is not only a risk to your pets, but a risk to you too. Forgive me if I missed the detail, but I assume the house is yours, and so you are entitled to tell him to leave and then enforce it. Not as easy as it sounds, I know, but you can, and must, do this for your safety and wellbeing.
For what it's worth, my advice would be - today ideally:
While he's out at work, change the locks.
Pack up his belongings - divide them into things he needs right now, and things he can have later.
The things he needs right now - put in bags next to the door or take them to his work (if that's possible). Do you have a shed or a garage you can put the rest in?
Message him to tell him the reasons why you have reached the end of your limit - the name calling, the lack of respect, the lack of care and help and reference how the deliberate harm to your pets is the final straw, and you need to him to leave now.
Write down all the worst examples from the past few weeks/months - this can be evidence for you to refer back to.
There will be places he can go, and if there genuinely isn't anyway, book him a cheap Travelodge for the weekend and he can then sort himself out. He's 24, he has money and he can decide on what to do next.
Tell his siblings - they don't have to take sides or do anything, but they need to know what he's doing and what you now need to do to protect yourself.
If you expect him to come home and try and force his way in - is this his style? - then call 101 and log your concern - give the example of him trying to harm the dogs and anything else that makes you fearful (such as threats and violence), and have it logged that you are removing him from your home.
I know you don't want any other family involved, but do you have friends who can come and just be at the house with you while you do this, or when you expect him to reappear?
You have had the most horrendous experience with his father and now with him, and I am so sorry. You deserve so much better and now is the time to take back control, as terrifying as it must seem. It sounds like you are beginning to actually start living again, and you must focus on this.
Sending love and strength, and know that we're cheering you on.