Below are some homeopathic suggestions for cats with urinary problems. I found them on my homeopathy for cats, Pet Remedy Cart. The charts are a life saver if you want use holistic remedies for your cat you can find the charts at petremedycharts .com

Urinary Bladder Stones
The homeopathic remedy, Berberis 30c can give relief and promote normal urination. I would choose this remedy for the older cat whose liver may not function properly and cause gravel. Many lab results confirm that the calculi consist of phosphates. Following veterinary diagnosis I frequently use Calcarea Phosphorica 30c. It can be given as dry dosed once weekly for 6-8 weeks. For prevention, I would use: Calcarea Phosphorica 30c. I give 1 pill crushed to a powder and put in the mouth ('dry dose') twice a month. This may help prevent or reduce occurrence of this condition.
Only choose and use one homeopathic remedy at a time. The charts explain exactly how to give the remedy and do the dosing.

Cystitis - Urinary Tract Infection
Apis mellifica 200c or 30c. For the warm, thirst-less, restless or listless animal that may act indifferent. The animal who needs this remedy often has symptoms of pain, straining and burning at the end of urination. Sarsaparilla 30c can be used if the symptoms are worse at the end of urination: blood or mucous may pass after bladder has emptied. INTENSE pain that causes the cat to cry out in anticipation of urination or at the end of urination.