Lady A we had a cat that was subject to cystitis as a result of being run over. Eventually we found that giving her a 50 milligram vitamin c pill everyday meant that she was rarely afflicted. It alters the acidity of the urine which makes it harder for the bacteria to breed, It became her party trick as she was rewarded with three pieces of Go-Cat when she took the pill, no science diets back then. Friends couldn't believe their eyes when she came to me and let me pop the pill down her throat without any fuss.
I've just weighed my eight month old kittens to give them the correct dose of wormer - Ginger weighs 11 lbs, just over 4.9 Kg and is still growing.