Hi everyone, I have this problem that just started a couple days ago. I have 3 cats the brother and sister are 7 years old and my oldest is 16 years old , and all my 3 get along great. This past Tues I went out for a couple of hours and came back home and everyone was in a uproar my younger cats had there tails all puffed but my oldest didn't. My oldest cat was behind my bed and was growling etc... He was acting like he didn't know where he was and he acted like it was his first time at my place. I tried to pet him make him feel comfortable and he didn't even care, he just kept growling at my other cats when he saw them. So I kept him in my room with me with my door shut until the next day everything seemed back to normal until tonight. My daughter and I just finished eating and relaxing on the couch and out of no where we heard a cat growling and we seen my female ( 7yr old) and my oldest cat running down the hallway into the livingroom. My oldest cat was growling and hissing but his tail wasn't puffed but my female cat tail was all puffed and even her brother's tail was puffed cause he was startled by what was going on. Now my oldest cat is under my couch and when he sees both of my other cats he starts growling so I don't know what it could be???