A new study out of JAVMA just gave you the data to justify prescribing renal diets in Stage 1 CKD cats.

A new study out of JAVMA just gave you the data to justify prescribing renal diets in Stage 1 CKD cats. The question now is whether you are having that conversation early enough.

Most veterinarians know the renal diet conversation. The cat is Stage 2, the creatinine is climbing, and you are trying to convince an owner to switch their fifteen-year-old tabby off the food she has eaten for a decade. It is a hard sell under ideal circumstances and an even harder one when the cat is already symptomatic and the owner is scared.

A new retrospective study published in the Journal of the American Veterinary Medical Association suggests that conversation needs to happen much earlier and now there is real data to support making it.

Researchers analyzed medical records from 1,430 cats diagnosed with early-stage chronic kidney disease across veterinary practices in the US and Canada. Of those, 839 were consistently treated with a veterinary therapeutic renal diet following diagnosis, and 591 were not. The results across all early CKD stages were consistent and significant.

Cats in Stage 1 CKD treated with a renal diet had a 45% lower hazard of progressing to a more advanced stage compared to untreated cats. The median time to progression was 20 months in treated cats versus 9 months in untreated cats — an 11-month difference from a dietary intervention alone. Stage 2 cats with creatinine within the reference interval showed a 46% lower hazard of progression, with treated cats progressing a median of 19 months later than untreated cats. Even Stage 2 cats with creatinine above the reference interval showed a 41% lower hazard of further progression, with median time to progression of 21 months in the treated group versus 12 months in untreated cats.

The survival numbers are equally compelling. Cats treated with a renal diet had a restricted mean survival time of 31 months over a three-year follow-up period, compared to 26 months in untreated cats. That is five additional months of survival which is a 30% reduction in all-cause mortality, attributable to diet.

Why Stage 1 matters more than you may be treating it

Current IRIS guidelines recommend initiating a renal diet at Stage 2 and reserve dietary intervention in Stage 1 cats for those with elevated FGF23 concentrations. This study challenges whether that threshold is set in the right place.

The Stage 1 findings here are particularly noteworthy because this population is, by definition, pre-azotemic. These are cats where the creatinine is still within or just below normal range, SDMA may be mildly elevated, and clinical signs are minimal to absent. They are easy to monitor and easy to defer on. They are also, according to this data, the cats who stand to gain the most time from early dietary intervention — 11 additional months to progression compared to untreated counterparts.

The study authors acknowledge that IRIS Stage 1 CKD can be challenging to diagnose, that cats are often asymptomatic, and that the diagnosis in a real-world retrospective dataset carries inherent variability. These are legitimate caveats. The study is also retrospective, not a randomized controlled trial, and the authors used targeted maximum likelihood estimation modeling to account for confounding — a sophisticated statistical approach designed for exactly this kind of real-world observational data, but one that cannot fully replace the gold standard of a controlled trial.

Notably, the study was conducted by researchers affiliated with IDEXX Laboratories, which manufactures SDMA testing. That relationship is disclosed and does not invalidate the findings, but it is worth knowing when you are reading the data.

The compliance problem is still your biggest barrier

The study found that only 33% of cats diagnosed with CKD had evidence of consistent renal diet use following diagnosis. Prior literature puts the range of owner adherence at roughly 45% to 66% once a diet is prescribed, which means the gap between recommendation and execution is substantial regardless of how early you start the conversation.

The researchers noted that 42% of cats in prior prospective studies did not successfully transition to a renal diet because either the cat or the owner was unwilling. That number should focus every clinician on the practical side of this recommendation: how you introduce the diet, how you frame the urgency, and how you support the transition matters as much as when you prescribe it.

Early diagnosis is the entry point. A cat diagnosed at Stage 1 has more time, more palatability options to trial, and an owner who is not yet in crisis mode. That combination is your best shot at successful long-term adherence.

The data is telling you to start sooner. The conversation just got easier to have.

Source: Journal of the American Veterinary Medical Association, 2026. Authors affiliated with IDEXX Laboratories Inc.