Post-operative complication grading system

Advancing post operative care in veterinary practice

RCVS Knowledge is proud to lead the way in improving veterinary care through the  post-operative complication grading system — a pioneering initiative designed to help veterinary teams consistently monitor and document surgical outcomes and complications, supporting effective auditing, and paving the way for future improvements in care. 

Why this matters

Veterinary medicine has evolved rapidly, but the pursuit of high-quality, evidence-based care remains constant. The post-operative complication grading system empowers practices to: 

• Record post-operative outcomes in a consistent and meaningful way 
• Identify trends and areas for improvement 
• Build a culture of continuous learning and clinical reflection.

Tailoring a grading system for veterinary practice

We are currently developing the RCVS Knowledge post-operative complication grading system, which will provide a consistent method for classifying surgical complications across species. This system will be tailored for: 

• Equine 
• Dogs and cats 
• Small mammals (e.g., rabbits, guinea pigs).

The grading system is being designed to be intuitive, practical, and grounded in both veterinary and human healthcare research. 

Following the release of the system, it will be used as the new grading system for the existing National Audit for Small Animal Neutering (NASAN) template, providing veterinary teams with a structured approach to recording post-operative outcomes. This update will support clearer tracking of surgical complications and help practices build a more complete picture of patient recovery over time. 

Built by experts, backed by evidence

The RCVS Knowledge post-operative grading system, due to be published in 2026, has been developed with input from a diverse advisory group representing a wide range of veterinary and related expertise.  

Contributors include: 

• RCVS Specialists in anaesthesia, surgery, and wildlife medicine, 
• Epidemiologists 
• Veterinary Nurses 
• General Practitioners 
• Human surgeons 
• Representatives from both the charity sector and animal owners.  

The system is being shaped by a comprehensive literature review and expert consensus, drawing on the Clavien–Dindo classification used in human healthcare and adapting it for veterinary application 

What’s next?

We’re preparing to: 

• Publish the grading system with species-specific designs and usage guides 
• Incorporate it into the NASAN template 
• Encourage adoption through direct outreach and professional endorsements.

Get involved

Whether you’re working in a referral hospital, first-opinion practice, or charity clinic, the RCVS Knowledge post-operative grading system offers a practical way to enhance surgical care.

By adopting the forthcoming grading system, your team can: 

• Strengthen internal auditing processes 
• Improve the consistency of post-operative records 
• Support reflective practice and clinical learning 
• Build confidence in managing surgical outcomes.

Endorsements and support

We are proud to have the support of leading organisations across the veterinary profession who recognise the value and potential impact of this post-operative grading system.

If you are interested in endorsing this project. Please email ebvm@rcvsknowledge.org