I am desperate for advice

I have a dog that I adore, have worked with her on behavioral issues and training. She is a love to me and my husband. She is also very aggressive towards my other dogs, very anxious. She does not rest well, I don't think she is a happy dog. My other dog has tolerated her advances and growling but now, she has decided to confront her. They got into such a brawl that my aggressive dog came out with blood dripping from her mouth, the other with blood all over and me with bruises trying to separate them. It turn out Jenna (Ms. Agression) popped a tooth as she grabbed onto Sophie's ear. I took them both in to the vet and they got first aid. It was a scene from a horror movie. I have never given up on a dog and I won't give up on Jenna but, she needs some kind of medication to help her life be less stressful. She lives in a constant state of alert, paces constantly. I just had the vet run all posible tests and she is in good health (her teeth are perfect, minus one). Don't ask me to rehome her, she was very shy when we took her in and it took a lot of patience, love and training to get her trust. Plus, i cannot just dump a problem into someone else lap. I need help, advice. She is 5 years old. Any help? I have a 3 lb Maltese that I also rescued. Jenna is only 18 but I am so afraid something horrible will happen. I keep them separated and that antagonize Jenna even more. Isolation isn't right or an answer. I'm sorry it is so long. And yes, I walk her for a good mile early morning and late at night.

Hello.  I'm pleased that you took medical advice - this is important because bite wounds so frequently become infected / turn out to be deeper or more serious 'crush' injuries than they initially appear.   Dogs are highly evolved for group living and at times, a scuffle will quickly establish heirarchical rules within the group, but sadly this is not always the case.

It sounds as though Jenna is not at ease in the social group at your home.  Has she had a check up to ensure that she is well in herself / not in hidden pain etc? -  because this can be a huge contributory factor.

Assuming that this turns out to be purely behavioural, there are a lot of options that you don't feel to be appropriate;  rehoming the dog that doesn't fit in;  keeping them separate; isolating one of them.  However, I do feel that you are running out of options.  I do not beleive - and it is not widely encouraged in the UK - that sedating a dog for behavioral reasons is appropriate.  After all, they would surely have to be sedated all the time.  Many sedated dogs still experience all the fear emotions that they would be experiencing normally; the sedative simply reducing their ability to react.  ACP in particular, which used to be commonly used to this purpose in the UK, is now known to cause this wealfare issue.    Rather than drugging dogs in order to help them to cope with a challenging environment, it makes much more sense to change the environment to one that is better suited to their needs.   This is a big ask, but it may be worth facing.

I have read back again and seen that you have already tried to rule out illness / problems with the patient.  Obviously I know very little about your particular household set-up and it may be that a different set up might solve the issue, so a good quality behaviour consultation with a certified behavioural expert may be worthwhile.  However, fixing behavioural issues is slow / long-term and hard work and I fear that drugging dogs for behavioural reasons is often unethical.  Therefore your vet (do run it by them) may reccommend a certified behavioural expert, or the option that we know you don't want to read.