Join Date: Mar 2010
Location: Ontario, Canada
Hi and welcome! I too would first rule out medical issues whenever faced with a sudden change in behavior. If it's not medical, then it could be their age, in that cats typically reach social maturity at or around the age of 2 (social maturity is when a cat's territorial instincts are fully developed), which sometimes results in problems between cats that previously got along well, and could account for Izzy's new behavior. But, before we deal with that, I suggest you first rule out a medical cause. Good luck and I hope Izzy is ok.