Gastric acid
The highest concentration that gastric acid reaches in the stomach is 160 mM in the canaliculi. This is about 3 million times that of arterial blood, but almost exactly isotonic with other bodily fluids. The lowest pH of the secreted acid is 0.8, but the acid is diluted in the stomach lumen to a pH between 1 and 3.
Feline lower urinary tract disease
Urine pH can be made more acid by increasing protein intake from animal and fish sources. Examples include human table scraps such as beef (steak/hamburger) and fish. Low cost urine test for humans can be used for monitoring and verifying that a cat's pH is below 6.8. A syringe can be used to suck up the urine from the floor when a cat urinates inappropriately and then squirted onto the test strip.