Gage was diagnosed last week with a urinary tract infection, on the basis of lots of struvite crystals in his urine, but no increased white cell count. He is taking antibiotics twice/day for 3 weeks. The vet also suggested changing his diet (he and Mila now eat Nutro Natural Choice lamb and rice lite (Mila's overweight)to something that would increase the acidity of his urine. They have eaten this food for years with no problems. The vet suggested "a high quality, perhaps high protein" food, but didn't name anything in particular, and she doesn't think he needs a prescription diet at this time. He goes back for a recheck in 3 weeks. I've never heard of a food that will acidify the urine. I'd appreciate advice.