Sodium Pyrophosphate

Sodium pyrophosphate is a phosphate salt that FDA includes on its GRAS list for animal feed. In cat food it helps hold texture and moisture and adds flavor. It also supplies phosphorus that is absorbed quickly, and a 2020 review linked high intake of soluble phosphate salts in experimental diets to kidney injury in cats. If your cat has kidney disease or is older, ask your veterinarian about the food.

Source: doi.org

Sodium pyrophosphate is added mainly as a palatability aid and texture agent. It is often part of the coating sprayed on kibble, where it helps the flavor appeal to cats. It also helps bind moisture. Along the way it adds phosphorus to the food.

Usually, yes. On pet food labels, sodium pyrophosphate most often means tetrasodium pyrophosphate, the form with four sodium atoms. FDA's GRAS list for animal feed has separate entries for sodium pyrophosphate and tetra sodium pyrophosphate, and the label does not always say which one was used. Both add phosphorus.

Source: ecfr.gov

Calcium and phosphorus work together in bones and in the kidneys, so their balance matters as much as their amounts. A 2020 review in the Journal of Veterinary Internal Medicine found that kidney injury in cats fed high soluble phosphate diets was more likely when phosphorus outweighed calcium. Phosphate additives raise phosphorus without adding calcium, which is why the ratio gets attention.

Source: doi.org

Pettings gives sodium pyrophosphate 2 out of 5 and lists it as a phosphate or acid additive. It appears on 12 of the 149 dry cat foods we list. The score reflects a common flavor and texture ingredient that also adds quickly absorbed phosphorus. Each food's page shows how it scores overall.