I have an 11 lb. Chihuahua. His urine was always at a pH of 8 with crystals forming. I put him on a urinary acidifier tablet for a couple of years and it did not do anything. I tried 1/2 teaspoon of ACV once a day and in only one week his urine pH went down to 5!!! Even the doctor was amazed when I told her what I did.