Our 2 year old moggie came in last night and his usual meow has changed, it's much higher in pitch and was still different this morning. I know he has different sound for different things but it's definitely changed. He seems fine in himself except a swollen lower lip which doesn't seem to bother him and he had last summer so we think might be a sting or allergic reaction to grass etc.
Anyone got any ideas what could have caused the change?