Inflammation in the bladder of cats can be due to infection, most often with bacteria. This is why it’s always important to have your cat examined by a veterinarian at Newport Harbor Animal Hospital (949-631-1030) to ensure there isn’t an infection that needs to be treated.
However, cats actually can have a weird condition where they have inflammation and we don’t know exactly why. When we don’t know exactly why a condition occurs, we call it ‘idiopathic’. This type of inflammation – we think is associated with stress in your indoor cat’s lives. A few things to offer your cat to ‘destress’ them:
1.  Multiple clean litter boxes – the rule of thumb in multi-cat households is a litter box per cat plus one
2.  Toys and play time – keep them mentally engaged
3.  Canned food – this increases water intake and therefore urination which helps to ‘flush the urinary system’
4.  Safe places to hide from other members of the household. They may feel the need for a break from and high places to monitor their domain
The Ohio State University has an Indoor Cat initiative to help keep Indoor cats healthy here is a link to a great pdf to get you started: https://indoorpet.osu.edu/sites/indoorpet/files/assets/documents/KeepingCatsIndoors-2013.pdf