Virbac HPM U1 Cat Urology Dissolution Dry FoodVirbac HPM Veterinary U1 Cat Urology Dissolution Dry Food This is a specialist clinical food that encourages water intake and balances urinary pH to help dissolve and reduce struvite stones and reduce oxalate stones Struvite stones are a formation of minerals to become hard deposits which collect in the bladder and urethra causing considerable discomfort, pain and difficulty urinating. In some cases they can cause a complete blockage in the urethra