Should a CKD cat's protein be restricted, or kept at an adequate level?

Keep protein adequate and high quality, and restrict it only moderately at advanced stages, when uraemia justifies it. Too early or too deep a protein cut causes harmful muscle wasting in this obligate carnivore. The decision follows the stage and muscle mass, assessed by the vet (IRIS, 2023; ACVN). Expert deep dive ### Why not cut protein early? The cat is an obligate carnivore whose metabolism depends on a high protein supply. Restricting protein before uraemia requires it causes lean-mass loss with no kidney benefit, and this sarcopenia worsens the outlook. At early stages, the priority stays phosphorus (ACVN; Tufts Petfoodology). Commercial renal diets contain reduced but high-quality protein, calibrated to cover needs while limiting nitrogen waste. ### When does protein restriction become justified? A moderate reduction is mainly discussed at advanced IRIS stages, once uraemic signs (nausea, dullness) appear. The aim is then to lower nitrogen waste from protein catabolism while still covering essential needs. Notable fact: the WSAVA muscle condition score, distinct from the body condition score, can reveal wasting in a cat of apparently normal weight, which fine-tunes the adjustment. Tracking creatinine, SDMA and muscle mass remains the only reliable guide. Comparison table | Stage | Protein direction | Risk watched | |---|---|---| | Early (1-2) | maintain, high quality | excess phosphorus | | Advanced (3-4) | moderate reduction if uraemic | muscle wasting | | All stages | never down to deficiency | sarcopenia | Petipedia's take Petipedia frames protein in CKD as a question of quality and the right level, not systematic cutting, leaving the decision to the vet.