Study summary · Cats · Kidney health · Ross et al., 2006
Clinical outcomes matter more than one blood marker.
A renal diet reduced uraemic episodes and kidney-related deaths in this trial. Overall mortality was not significantly different.
Why this study matters
For an owner, an illness episode is a more direct outcome than a change in a laboratory number. Reading these outcomes separately helps explain why a diet can have a clinically useful effect without improving every measured marker.
How the study worked
Participants
Client-owned cats with stage 2 or 3 chronic kidney disease.
What happened?
22 cats received a renal diet.
The comparison
23 received an adult maintenance diet.
What was measured?
Uraemic episodes, mortality and clinical measurements.
What the researchers found
| Outcome | Reported result | How to read it |
|---|---|---|
| Uraemic episodes | 0% on renal food; 26% on maintenance food. | An observed zero is not a guarantee for another cat. |
| Mortality | Kidney-related deaths were significantly reduced; all-cause deaths were not. | Cause-specific and overall survival are different outcomes. |
| Diet changes | Protein, phosphorus, sodium and lipid content differed. | The trial tests a whole diet, not one nutrient in isolation. |
Source access: abstract-based summary. University research record.
What strengthens the evidence?
Random allocation improves the fairness of a comparison, while masking can reduce the influence of expectations. Following household pets and measuring illness outcomes makes the research relevant to clinical decisions.
What limits the conclusions?
A small trial gives limited precision. Findings in cats already diagnosed with kidney disease should not be extrapolated to healthy cats. Multiple dietary changes prevent a clean attribution to protein restriction alone. This entry uses the published abstract; complete withdrawal data, allocation methods and funding disclosures have not been checked.
What the researchers concluded
The authors favoured the renal diet for reducing uraemic episodes and renal-related mortality.
Evidence.pet interpretation
This is evidence about management after a diagnosis, not prevention in a healthy animal. A cause-specific survival result should be described exactly that way; replacing it with an unrestricted “lives longer” claim would broaden the finding. Equally, a non-significant overall mortality result does not prove that the foods are equivalent. For an individual cat, the useful discussion with the treating veterinary team is how this evidence fits the diagnosis, food acceptance and monitoring plan. This study summary supplies context for that discussion, not a prescription or a target nutrient level.
Funding and author interests
Funding and author-interest statements were not available in the abstract reviewed. They remain unverified.
Read the original research
Ross SJ, Osborne CA, Kirk CA, Lowry SR, Koehler LA, Polzin DJ. Clinical evaluation of dietary modification for treatment of spontaneous chronic kidney disease in cats. JAVMA. 2006;229(6):949–957. doi:10.2460/javma.229.6.949.
Evidence.pet editorial summary · Study ID STU-006 · Source checked 22 September 2026. Strengths, limitations and interpretation are our editorial assessment, not a formal evidence grade.
Source checked: published abstract in the University of Minnesota research record. Full-text appraisal pending.