Oh Wayne - I certainly sympathise - 'cos poor old Ketchum gets beaten up off Dan. I reckon it's because when we rescued Ketchum he'd had his op., but when we got Dan he was a year old and had only just had his op., - maybe his King of the Castle vibes were still strong - and still are!!
Ketchum is so loving and head buts Dan, for which he gets a bat round the ear - poor boy. Needless to say he comes to me or hubby for lots of cuddling and scritching of the neck. He's a great big softy and never holds a grudge against Dan.
Maybe keeping Princess away from the others for a little while might make it easier for her. Ketchum always has HIS safe pace to go (under our bed or on it if he's alone!!).
Best of luck Wayne - I hope this sorts out soon.

Lynne