Gastric acid
The main constituent of gastric acid is hydrochloric acid which is produced by parietal cells (also called oxyntic cells) in the gastric glands in the stomach. Its secretion is a complex and relatively energetically expensive process. Parietal cells contain an extensive secretory network (called canaliculi) from which the hydrochloric acid is secreted into the lumen of the stomach. The pH of gastric acid is 1.5 to 3.5 in the human stomach lumen, the acidity being maintained by the proton pump H/K ATPase. The parietal cell releases bicarbonate into the bloodstream in the process, which causes a temporary rise of pH in the blood, known as an alkaline tide.
Vegetarian and vegan dog diet
Animal protein has a high acidic amino acid content (glutamic and aspartic acid), therefore, its nitrogenous metabolites that are excreted via the urine are acidic that make the normal range of a dog's urine pH 5–7. Plant-based protein is relatively lower in these acidifying amino acids, which can lead to urinary alkalization (pH > 7). Alkaline urine put dogs at an increased risk of developing strive crystals, dysuria, hematuria and obstructing the urinary tract which can have fatal outcomes. Vitamin C, potassium chloride, DL-methionine, cranberry (which promotes overall health of the urinary tract), as well as peas, brown rice, and lentils all promote GI health and urine acidification, and can be used to correct the alkalinity of urine. Acidifying ingredients should be used with caution because over-supplying a dog can lead to metabolic acidosis. Regular monitoring of the acidity of a dog's urine during the transition onto a plant-based diet, changes in the diet, and during periods of illness are recommended.