there's actually a setting that prevents cats from retiring because of permanent conditions, and another one that allows retired cats to become mediators. i believe that retired cats with no "titles" still help around the camp as well. one of the kits in my save was born with lower body paralysis and retired as soon as he aged up, but had the description "camp keeper". also, some disabled cats don't retire. iirc i've had cats develop vision impairments or lose a tail/limb and still be able to go on patrols and such. ^w^
Can confirm, I have a cat who was born paralyzed and when he aged up he retired but his description was "Excellent kitsitter" and he ended up becoming mediator. I've also had blind cats, deaf cats, cats with missing limbs/tails, cats with seizures, etc. all be able to go on patrols. I had a deaf leader once too!