Aggressive Grooming

This is probably the 4th time this has happened. My male cat, age 4, was playing normally this morning. Then out of no where he goes into this fit of aggressive grooming. Licking himself wall over, biting at his paws, his back and ears twitch, he hisses if I try to touch him (very abnormal, he’s a cuddly/clingy cat). I’ve taken him to the vet and they said he probably just has seasonal allergies. But his behavior gets so weird usually for 24 hours and then he seems to go back to himself. Has anyone seen this before?

Hello!  I think that in some situations, over-grooming can be a pain or stress response.   You used the present tense there ('gets all weird for 24 hours and then he seems to go back to himself') which suggests that the behaviour may have happened several times before.   How often does it happen, and when?  Is it predictable (eg after a fatty meal etc)?  Is his bladder full at this time?  It may help to keep a diary of anything you can remember about your cats day when it happens and presenting again if you are worried.  If ongoing, some vets might propose trialing pain releif or trying to rule out pancreatitis / bladder problems / underlying injuries etc. I hope that you manage to solve the mystery - or better still that it never happens again!