# Evaluation of Hemogram-Derived Inflammatory Markers in Healthy Cats

## TL;DR

This study establishes standard blood-based inflammation marker ranges in healthy cats to help veterinarians make more accurate disease assessments.

## Contribution

The paper provides the first standardized reference intervals for six inflammatory blood ratios in clinically healthy cats.

## Key findings

- Reference ranges for NLR, MLR, PLR, SII, AISI, and SIRI were established in healthy cats.
- No significant differences in inflammatory markers were found between male and female cats.
- The findings offer a practical tool for interpreting inflammation in feline patients.

## Abstract

This research focuses on establishing standard reference values for specific blood ratios in cats to improve diagnostic precision. Key markers like the neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), platelet-to-lymphocyte (PLR), systemic immune–inflammatory index (SII), aggregate systemic inflammation index (AISI), and systemic inflammatory response index (SIRI) are increasingly favored in veterinary medicine as they are easily derived from routine blood tests at no extra cost. These indices have proven essential for predicting outcomes in acute inflammatory, cancerous, hepatic, and gastrointestinal conditions, as well as serving as early indicators for heart and lung diseases. The study identified the following reference ranges: 0.8–7.1 for NLR; 0.1–0.6 for MLR; 22.7–374.6 for PLR; 130–2454 for SII; 39.5–1542.8 for AISI; and 0.2–6.1 for SIRI. These findings provide a practical clinical tool, allowing veterinarians to quickly compare patient data and make more accurate prognostic and predictive assessments across various diseases.

In the field of veterinary medicine, hematological indices such as the neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), platelet-to-lymphocyte (PLR), systemic immune–inflammatory index (SII), aggregate systemic inflammation index (AISI), and systemic inflammatory response index (SIRI) are increasingly recognized as cost-effective indicators of systemic inflammatory activity. Despite their diagnostic potential, standardized reference intervals for these metrics remain undefined in clinically healthy feline subjects. Consequently, the primary objective of this investigation was to establish baseline reference ranges for these inflammatory ratios in cats, thereby facilitating more accurate clinical interpretations and diagnostic assessments in feline practice. Clinical records were reviewed retrospectively, and cats showing no abnormalities on physical examination and presenting laboratory values within established reference ranges were included in the analysis. Following the sex-based analysis of 88 samples, the reference intervals were defined as follows: 0.8–7.1 for NLR; 0.1–0.6 for MLR; 22.7–374.6 for PLR, 130–2454 for SII, 39.5–1542.8 for AISI, and 0.2–6.1 for SIRI. Comparison by sex did not demonstrate statistically significant differences in any of the analyzed indices. These findings may offer a significant clinical framework for the interpretation of hematological inflammatory markers in feline patients.