I am sorry for your cat’s grief. Lower urinary tract problems such as these are difficult to control. There is no simple answer. Dietary management can be one piece of the puzzle. It appears you have pursued this angle. Use of distilled water to minimize minerals is advocated by some veterinarians. Recurrent urinary tract infections can be a leading cause as well. For difficult cases such as yours frequent culture and sensitivity of the urine can be helpful. Due to expense, some veterinarians will try cyclic antibiotic use, 2 weeks on 2 weeks off while alternating the antibiotics. Yes, this can be for the life of the cat. It remains a fact that there is an individual predilection for this problem. Two male cats can be on the same diet, drink the same water, have the same activity, yet only one will have problems with blockage. That is the piece of the puzzle we are still missing.
