Personality change
I need help on my dogs sudden personality change to see if there is anything I can do to have a happy pet family. Some backstory: I adopted my dog (rottweiler/pit/doberman mix) when someone dumped her and her brother off at a vet clinic I used to work at. They were about 2 months old when they were brought to us and after treating them for some parasites, I took her home. Luckily, my work had a doggy daycare where I would take her every day that I worked and she learned how to socialize with other dogs and people. I also enrolled her in puppy training classes, but just the level one where they teach the basics. I knew for her breed and their stigma that it was important to get her socialized and trained. Of course she had dogs she didn't get along with but she never got into fights. After I got her, I stayed working at the clinic for about another 7 months before I left for a new job and while she was going to daycare for free during that time, when I left I just couldn't afford $200 a week for daycare so I unfortunately had to stop taking her. I have three other dogs at home, a 4 year old, a 3 year old, and an 11 year old, all smaller than her, but I was lucky she got more of a pit size as shes only about 54 pounds. Growing up she loved playing with any dogs, especially the ones at home, and never had an issue with the cats. She always has had her own space as she has always slept in my room, in her own crate, while the other dogs slept in the living room and the other bedroom. I was afraid of food aggression so from the get go i separated her from the other dogs while eating, and everyone has to wait until everyone is done before being put back together. They are all mostly indoors with the exception of time we are out of the house for longer periods of time and they have a nice backyard to run and play in. So all in all, I think she has always had her own space and never felt like she had to stay with the group. She has always been stubborn and would definitely challenge any behaviors told and would only listen to certain people. There was always a power struggle, but once she hit about 7 months she had gotten out of that. It seemed like the change happened literally overnight. At this point the rott is about 10 months old and we had scheduled her spay for the week coming. In the morning about 1 month ago I heard one of my dogs screaming and I could hear growling so I went to see what was happening (as they like to play rough) and I saw my rottweiler pinning down my 4 year old dog and had her by the throat. My mom rushed out and we broke up the fight, of course sustaining hand injuries. I thought it was a fluke and something must have happened like they fought over a toy perhaps. The rott stayed outside for most of the day, and we placed the 4 year old in her crate and had the rott come in to see what she would do, but protected. Everything seemed fine and she didn't pay any attention to her but to be safe we kept them apart, but able to see each other the rest of the day. The next day everything seemed fine so we tried to reintroduce them. 5 minutes of them playing went by and the rott initiated another attack, this time grabbing her face. We broke up the fight again and decided they couldn't be together. They could see each other, but they couldn't be out together. After the fights it seemed like the 4 year old dog was having some ear issues so we took her in and found out she had an ear infection. It was treated but we were thinking it was possible that the weird smell triggered the rott. She also started attacking the cats in my room and had knocked over my mom to chase the cats in her room and almost killed one. All of this was over the span of about 3 days and all the while she was playful with the other 2 dogs. Working as a vet tech I saw a handful of times where dogs who were not spayed/neutered started to become aggressive but the bad behavior already became a habit so most of the time the surgery didn't help much. I didn't want the aggression to become a habit so I kept her separated from the one dog and cats and moved up the spay date. I read that it could take up to 6 weeks for the hormones to settle so I had to hold on to the hope she would. About 2 weeks after the surgery and she still had her cone on, my mom accidentally let out the 4 year old dog when the rott was out, and even with the cone and not feeling her best, she still tried to attack her. Also to note the 4 year old dogs ear infection was cleared up, so there was no odd smell and we bathed her to see if maybe she had a odd odor the rott picked up, but still she attacked. At this point I'm at a loss. I don't know why she changed over night and now I'm worried about my dogs and cats. Does anyone have advise on how to fix their relationship and her aggression or can see what triggered her? I love her but I have to think about the safety and well being of my other animals too.