Hyperphosphatemia is defined as an abnormally elevated level of phosphorus in the blood and is universally recognized as one of the most significant predictors of mortality in feline Chronic Kidney Disease. In a healthy animal, the kidneys act as a filtration system to excrete excess dietary phosphorus into the urine. However, as kidney function declines, this filtration capacity is lost. Phosphorus subsequently accumulates in the bloodstream. This retention triggers a destructive chain reaction known as Renal Secondary Hyperparathyroidism where the body strips calcium from the bones to balance the excess phosphorus. Furthermore, high phosphorus levels can cause mineralization where calcium and phosphorus bind together to form hard deposits in the soft tissues of the kidneys. This process accelerates the destruction of the remaining nephrons. Consequently, the management of phosphorus is considered the cornerstone of CKD therapy. It is primarily achieved through the use of renal therapeutic diets which are formulated with restricted phosphorus content. In more advanced stages, phosphate binders are added to food to trap phosphorus in the gut and prevent its absorption into the bloodstream.
Disclaimer: This content is for educational purposes only and does not constitute veterinary medical advice. Always consult with your primary care veterinarian or a veterinary internal medicine specialist regarding your cat’s specific condition.