- The chronic diseases of advancing age--hyperthyroidism, kidney disease and diabetes--can cause a cat to have to urinate so often and in such volume that the cat can't always make it to the litter box. Treating the health problem should resolve the litter-box issues.
- Some declawed cats experience real or phantom pain in their paws and seek out soft surfaces for their bathroom chores. Giving medication as needed for pain relief and providing litter that feels soft underfoot should make the cat comfortable enough to start using the box again.
- Cats suffering from bladder stones or crystals often associate the litter box with pain and feel more comfortable urinating on a towel or other soft surface. Giving the cat a second box in a new location could overcome litter-box aversion.
- Cats who suffer from arthritis may have difficulty getting in and out of the litter box and will urinate on a towel or pile of laundry left on the floor instead. Medication will relieve the pain and improve the cat's mobility.
- Obese cats often have mobility issues and have trouble getting in and out of the litter box. A box with no top and very low sides is more manageable for an obese cat than a deep or covered litter box is.
