Iron‐Limited Erythropoiesis in Dogs and Cats: A Systematic Review and Meta‐Analysis of Current Evidence Examining Mean Corpuscular Volume, Mean Reticulocyte Volume, and Reticulocyte Hemoglobin Content

ABSTRACT Background Iron‐limited erythropoiesis (ILE) is a common condition in dogs and cats, which can lead to anemia; therefore, monitoring with erythrocyte and reticulocyte indices is recommended. Objectives To compare the values of mean corpuscular volume (MCV), mean reticulocyte volume (MCVr), and reticulocyte hemoglobin content (CHr) in dogs and cats with ILE. Methods Systemative review and meta‐analysis. We conducted a systematic search using PRISMA criteria in PubMed, ScienceDirect, and Google Scholar up to 2024. It focused on erythrocyte and reticulocyte indices, such as MCV, MCVr, and CHr, in dogs and cats with ILE. Results This meta‐analysis included eight articles. For dogs, the random effect sizes were 2.86 (0.55–5.18) for MCV, 2.18 (0.87–3.58) for MCVr, and 4.73 (1.37–8.08) for CHr. For cats, the effect sizes were 0.85 (0.19–1.5) for MCV, 3.45 (0.49–6.41) for MCVr, and 2.51 (0.29–4.74) for CHr. The analysis revealed I2 values of 97%, 94.3%, and 98.2% in dogs, and 63.1%, 93%, and 95.1% in cats, for MCV, MCVr, and CHr, respectively. The overall random effects were 1.98 for MCV, 2.54 for MCVr, and 3.87 for CHr. Conclusion and Clinical Importance The findings revealed significant differences in reticulocyte indices, MCVr in cats, and CHr in dogs between the ILE‐affected and the healthy groups. Considerable variability among studies indicates caution in generalizing findings and makes conclusions less definitive.