I donīt have cats, but in my case with dogs...... you are the only one who will know when itīs time...... you just feel it...... for me sometimes when a dog died I felt the "urge" to get another one, not sure why but I just felt it, thatīs how I got Ninja.....I never regreted it but it may have been too soon for others as Ranma (the RB) just passed a few days before........and other time it may take you a while longer....when my Phantom died I was left with China and Ninja and although I wanted to get another one so bad as I felt with a blank but still this day I havenīt as I havenīt fel "it" maybe I just havenīt found "the" dog....... for me I know I could not live without dogs.....they are my life and I donīt feel like Iīm replacing the ones that just went to the RB, but that īs just me I need to have a canine companion and they sure help heal......you have your mind on them and not the pain......because pain will always be there but you can think of your pet in a happier way having that "someone" to cheer you up........