Emily Yuguchi¹, Jude Bradbury¹, Emma Driver¹, Sian Beard², Anne Carter³, Dan O'Neill¹, Emily Hall¹

¹Royal Veterinary College, London, United Kingdom. ²Office of National Statistics, Manchester, United Kingdom. ³Foods Connected, Londonderry, United Kingdom

Objectives

Effective triage and clinical decisionmaking enable earlier recognition and treatment of canine HRI, improving prognosis. The original 2021 VetCompass grading tool for HRI was updated in 2026 following validation in an emergency-care setting. This study evaluates the 2026 version of the grading tool for effectiveness in primary-care practice.

Methods

Dogs with HRI during 2023 were identified from anonymised primary-care clinical records within VetCompass. Presenting clinical signs and case outcomes were extracted. Each HRI case was retrospectively graded using the revised 2026 grading tool. Relationships between HRI grade and fatality were evaluated using binary logistic regression and the grading tool’s predictive ability using the area under the receiver operator curve (AUROC) .

Results

From a random sample of 500,000 dogs, 303 HRI cases were identified; annual incidence risk was 0.06% (95%CI 0.05-0.07%) with 13.53% (95%CI 10.13-17.84%) case fatality. Using 291 cases with ≥1 recorded clinical sign, 33.33% were graded mild (1.03% died, n=1/97), 52.92% moderate (5.84% died, n=9/154), and 13.75% severe (77.50% died, n=31/40. Cases graded severe had 263 (95%CI 27-2543) times the odds of fatality compared to cases graded mild; the AUROC was 0.91 (95%CI 0.86-0.96) suggesting good-excellent prediction.

Statement: Impact/ Clinical Significance

The annual incidence risk of HRI in UK dogs under primary-care increased by 50% from 2016 (0.04%) to 2023 (0.06%), emphasising the need for enhanced veterinary awareness and client education. The revised 2026 VetCompass HRI grading tool is shown here to support clinical decision-making through reliably identifying dogs at increased fatality risk from HRI.