The subject of intentional breeding or meat rabbits is prohibited. The answers provided on this board are for general guideline purposes only. The information is not intended to diagnose or treat your pet. It is your responsibility to assess the information being given and seek professional advice/second opinion from your veterinarian and/or qualified behaviorist.
LEADERS: Azerane Bam BinkyBunny JerseyGirl LBJ10 LittlePuffyTail LongEaredLions RabbitPam
Try limiting him to a bathroom. It is better than him going outside, especially if he is an indoor only cat
Is he actually being treated for his UTI or is it just the diet change?
Have there been any changes in litter or box type? How many boxes does he have? If one of the boxes is covered, does he have the option of a non-covered box? Have you tried different litter types? Has the box been moved? Is he neutered?
Is it possible to get him a new box, with different litter, placed in a new location that he won't have the pain association with?