Abby (6yr old GSD X Boxer) has attacked four other animals (feral cat during a walk, Kieber, and two of my cats, Binky and Raiden). None where injured (Binky does have a small scratch on his ear) and none where near food/treats or anything of value to her. The feral cat was sunning itself, Kieber was three feet away from here, Raiden was under a table and Binky was across the kitchen. She also has started growling at the other dogs/cats more. It is to point that Zane and Deputy are keeping away from her and Zane is frantic to get into my room at night (Dep is in Dementialand half the time, so no idea if he even notices). When we came home yesterday after noon, she barked at us and attempted to hide under the couch. We where coming in the same door as always and weren't carrying anything that would freak her out to that extent. She was barking at us like she does at strangers. She had her yearly exam in Feb and the vet did not find anything. She is UTD on shots,spayed, and is on the same food and schedule as always. At first I thought it was because of us bringing Kieber home, but after the attacks on the three cats, I'm not so sure. She has always been an aloof dog, would only come to you to be petted once or twice a day and that has not changed, she is still wanting the same amount of attention and is not acting clinging at all. As soon as the vet has an opening I'll take her in. She is separated from the other animals when we are gone and at night. Does this sound like a thyroid issue? Vision?