Elevated concentrations of serum phosphate are linked with progression and increased case fatality rate in animals and humans with chronic kidney disease. Elevated concentrations of serum phosphate can be a risk factor for development of renal and cardiovascular diseases or osteoporosis in previously healthy people. In rodents, an excess intake of dietary phosphorus combined with an inverse dietary calcium : phosphorus ratio (<1 : 1) contributes to renal calcification. Renal injury also has occured in cats fed experimental diets supplemented with highly soluble phosphate salts, especially in diets with inverse calcium : phosphorus ratios. However, not all phosphorus sources contribute similarly to this effect. This review, which focuses on cats, summarizes the published evidence regarding phosphorus metabolism and homeostasis, including the relative impact of different dietary phosphorus sources, and their impact on the kidneys. No data currently shows that commercial cat foods induce renal injury. However, some diets contain high amounts of phosphorus relative to recommendations and some have inverse Ca : P ratios and so could increase the risk for development of kidney disease. While limiting the use of highly soluble phosphates appears to be important, there are insufficient data to support a specific upper limit for phosphate intake. This review also proposes areas where additional research is needed in order to strengthen conclusions and recommendations regarding dietary phosphorus for cats.
Bibliographical noteFunding Information:
Funding provided by Nestle Purina PetCare and Waltham Centre for Pet Nutrition. The authors thank the sponsors, the Purina Institute and the Waltham Petcare Science Institute, for supporting this endeavor.
Expenses related to the development of the manuscript (travel, meeting and honoraria) were offset by the sponsors, the Purina Institute and the Waltham Petcare Science Institute. Laflamme is a consultant for Purina. Backus receives support for his nutrition program from a Purina endowment, has consulted for both sponsors, and has received other support for his nutrition program from both sponsors and Hill's Pet Care. Butterwick and Czarnecki‐Maulden are employed by the sponsors. Elliott has served as a consultant for Waltham and has received research funding from Royal Canin. Fascetti serves on an advisory council and is a frequent speaker for the Purina Institute, and has received support for her nutrition program from both sponsors and Hill's Pet Care.
© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.
PubMed: MeSH publication types
- Journal Article