What to do with an elevated SDMA on a preanaesthetic profile

Recent evidence suggests that inclusion of high levels of inorganic phosphate in prepared diets for cats can have negative effects on renal health as is thought to be the case for human health. In this lecture I will review the basic understanding of the physiology of phosphate homeostasis in the cat and present and critically analyse data from recently published nutritional studies. I will also review the evidence that disturbances in phosphate homeostasis accompany the early stages of chronic kidney disease in the cat. Particular focus will be given to the phosphaturic hormone FGF23 as a marker of phosphate overload and its use in identifying cats in need of dietary phosphate restriction and monitoring their response to such treatment.

• 1.Define the roles of fibroblast growth factor 23, alpha-klotho, parathyroid hormone and calcitriol in regulating phosphate homeostasis
• 2.Critically evaluate the published literature on dietary phosphate and its effects on kidney function in the cat
• 3.Define the earliest evidence of disturbances of phosphate homeostasis in cats with pre-azotaemic chronic kidney disease
• 4. Define the use of serum FGF23 in identifying cats in need of dietary phosphate restriction and in monitoring their response to treatment.