Like in the title my 6 year old cat, tortellini, recently had surgery to remove a sarcoma from her upper left shoulder. Her entire leg shoulder blade was removed to try to save her from he cancer.

She is a calm, loving, friendly cat and always has been. The problem is she will be cuddling or laying with us and her temperament will change like a flip of a switch. She will start meowing uncomfortably and get low to the ground. She will stay low and slink around biting random things which she has never done in her entire life. A few times she has come at me and my GF aggressively trying to bite us which she would never do normally.

I understand she is probably in pain and that is what is causing this but this will happen anywhere from 45 seconds to 3 minutes and then she goes right back to her normal self like nothing happened. I am wondering if this is indicative of Feline Phantom Limbg Syndrome or just normal pain after such a big surgery. I also wonder if she could have came out of surgery with PTSD or something. I am just confused as to what is exactly going on and want to help my cat in anyway possible and want her to be comfortable. We have taken her to the vet but she only does this like once or twice a day so they never see exactly what I'm talking about. Please help.