Hello everyone. A week ago my 11 month old dog Ziggy got spayed and I am very worried because now she is being aggressive. I adopted her when she was 3 months old, but a month after, I had to move in with my parents and brother because my landlord decided he no longer allowed pets. I didn’t want to give her up. She used to be a very anxious and fearful dog, but gradually she gained confidence and was the sweetest dog until now. The first incidence occurred 5 days after the surgery. She was sleeping by the door when my dad came home and she just jumped, bit him and drew blood. She continued lunging until I caught her. She was running a fever then, so I thought that might be the reason. The next morning she seemed fine, but as my brother was petting her on the chest, she did the same thing. She doesn’t just growl. She bites immediately and continues lunging. Same incident with my brother today. She even followed him into the other room and continued lunging until I stopped her. I am very confused. Although my father never paid her much attention, my brother used to play with her and she used to be very happy to see him. She showered him with kisses as soon as he walked into the room. No aggression towards me or my mom at this point. She has never been abused by anyone in the family. I work from home and spend a lot of time with her and we have a great bond. I know for a fact that another dog from the same litter (4 puppies were found in a cardboard box on the street) has always been very aggressive and the family is about to give her up. Has anyone experienced something similar? Should I have not spayed her? I will be moving out of my parents house soon, but I don’t want to exacerbate the situation. What can I do? Look for a trainer right away? I’d appreciate any advice you might have!