IRIS Guidelines

The mission of IRIS is to help veterinary practitioners better diagnose, understand and treat renal disease in cats and dogs.

One of the organization's primary objectives is to establish an internationally recognized set of guidelines on the diagnosis and assessment of renal disease in small animals (IRIS Staging of Chronic Kidney Disease, CKD). In conjunction with these the board has also developed guidelines on the management of cases of CKD (IRIS Treatment Recommendations). Recently we have added guidelines on Grading Acute Kidney Injury (AKI) and the results of the IRIS Canine Proteinuria Consensus Project have been published online. The IRIS AKI Grading system and the IRIS CKD Staging and Treatment guidelines are works in progress that will be amended and updated as further information becomes available.

These guidelines are reviewed and updated by the IRIS Board regularly and you will find the most recent version on the website.

  • Introduction: What's New in the 2026 IRIS Guidelines

    The IRIS Board has reissued its core reference documents — CKD Staging, CKD Treatment Recommendations (Dogs and Cats), and AKI Grading — as 2026 revisions. Most of the diagnostic framework is unchanged from the 2023 guidelines currently in wide clinical use, but anaemia management has been formalized with clearer triggers. Both the dog and cat treatment documents now specify definitive haematocrit thresholds for initiating treatment (dogs: treat at HCT <30%, or persistent anaemia at 30–35%; cats: treat at HCT <25%, or persistent anaemia at 25–28%), replacing the older, less precise guidance. The documents also now explicitly list HIF-PH inhibitors (e.g., molidustat) alongside darbepoetin and transfusion as treatment options — reflecting newer therapeutic classes.

    Additionally, time frames for the assessment of hypertension have been clarified and stratified by severity.

  • As the leader in veterinary nephrology, IRIS has a responsibility to provide practicing veterinarians with evidence-based guidance for diagnosing, treating, and managing kidney disease. Our responsibility includes providing the most useful direction on how to interpret diagnostic information. The inclusion of SDMA values in the IRIS CKD Staging Guidelines is the next step in improving not only early diagnosis of CKD but also tailoring treatment of CKD to individual patients. The IRIS Board recommends using both serum creatinine and SDMA to enhance our ability to evaluate renal excretory function. These two surrogate markers are complimentary to each other. Another change the IRIS board has recently made is the expansion of Stage 2 for dogs and a corresponding reduction in size of Stage 3 for dogs. This change was made to reduce the large variability in clinical signs and treatment needs for dogs in the previously large IRIS Stage 3 category.

    Staging of chronic kidney disease (CKD) is undertaken following the diagnosis of CKD in order to facilitate appropriate treatment and monitoring of the patient. Staging is based initially on fasting blood creatinine, assessed on at least two occasions in the stable patient. The patient is then substaged based on proteinuria and systemic blood pressure.

    Based on these categories, some empirical recommendations can be made about the type of treatment it would be logical to use for these cases. In addition, predictions based on clinical experience might be made about the likely response to treatment.

    » IRIS Staging of CKD (modified 2026) - (PDF)

    » IRIS CKD Pocket Guide

  • All treatments for chronic kidney disease (CKD) need to be tailored to the individual patient. The following recommendations are useful starting points for the majority of animals at each stage. Serial monitoring of these patients is ideal and treatment should be adapted according to the response to treatment.

    Some of the suggested treatments are not authorised for use in dogs and/or cats and recommended dose rates are therefore empirical. It is the veterinarian's duty to make a risk:benefit assessment for each patient prior to administering any treatment.

    » IRIS Treatment Recommendations (modified 2026, PDF)
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    Cat

    DISCLAIMER: Although every effort has been made to ensure the completeness and accuracy of the information provided herein, neither the IRIS Board nor Elanco Animal Health assumes any responsibility for the completeness or accuracy of the information. All information is provided "as is" without any warranties, either expressed or implied.

  • Acute kidney injury (AKI) represents a continuum of renal injury from mild, clinically inapparent, nephron loss to severe acute renal failure. To emphasize the concept of AKI as a continuum, IRIS recommends that it be graded to accurately characterize the severity of the disorder. The IRIS AKI Grading scale (I-V) for dogs and cats is based on fasting blood creatinine determination and clinical parameters, such as urinary flow rate.

    The development of this scheme was led by Dr. Larry Cowgill of the IRIS Board and was adopted by the IRIS Board, provisionally in 2012 and finally in 2013. The IRIS Board is now seeking feedback and recommendations for modifications from the American and European Societies of Veterinary Nephrology and Urology (ASVNU and ESVNU) and from the wider veterinary community.

    The IRIS AKI Grading scheme is intended to aid the development of appropriate prognoses in patients with AKI. In the future, the Board intends to expand these guidelines to include recommendations for diagnostic testing and for treatment and monitoring of AKI, paralleling the widely accepted IRIS guidelines for Staging and Treatment of Chronic Kidney Disease (CKD).

    IRIS grading of acute kidney injury


  • IRIS Consensus Recommendations for Treatment of Canine Proteinuric Kidney Disease

    At its 2011 meeting in Denver, the IRIS Board approved the formation of a study group to develop a consensus report entitled "Best Clinical Practices for Proteinuric Kidney Disease in Dogs". Two Board members, David Polzin and Larry Cowgill, serve as the co-Chairs of this group. The aim of the project was to utilize currently available evidence and group consensus to develop a series of clinically applicable recommendations for diagnosis and management of these patients.

    To cover the wide array of patient presentations, geographic variance and means available following focused topics were developed:

    1. Diagnostic Investigation of Dogs with Suspected Glomerular Disease,

    2. Standard Therapy of Dogs with Suspected Glomerular Disease,

    3. Immunosuppressive Treatment of Dogs with Glomerular Disease Based on Established Pathology,

    4. Immunosuppressive Treatment of Dogs with Proteinuric Kidney Diseases Absent Histopathologic Diagnosis,

    5. Immunosuppressive Treatment of Dogs with Suspected Glomerular Disease and Serologic Evidence of A Possible Causative Agent.

    Further details on this project are available in the IRIS Newsletter. This work is published as a supplement to the Journal of Veterinary Internal Medicine and is available online. The Board hopes this project will serve as a model for the development of future recommendations in nephrology, as well as other fields in veterinary medicine. The development of this report, and its inclusion as a journal supplement, were graciously supported by Novartis Animal Health, acquired by and now supported by Elanco Animal Health, a division of Eli Lilly and Company.