Electrocardiogram Alteration and Hematologic Parameters in Dogs with Iron Deficiency Anemia

Iron deficiency anemia (IDA), a common yet under recognized condition in canine populations, presents systemic health risks, including cardiovascular dysfunction. While, electrocardiogram (ECG) abnormalities associated with anemia have been documented in humans and felines, species-specific evidence in dogs remains limited. This investigation utilized a prospective case-control design to evaluate ECG alterations in dogs suffering from IDA and their relationship with hematological severity. a cohort of 40 client-owned dogs diagnosed with IDA (hemoglobin [hb] <12 g/dl, microcytic/hypochromic erythrocytes, confirmed via serum iron and ferritin levels) and 60 age-matched healthy controls underwent standardized hematological profiling and six-lead ECG assessment. analyzed parameters included heart rate (HR), QRS complex amplitude, ST-segment morphology, and corrected QT interval. Comparative analysis revealed marked ECG deviations in anemic dogs relative to controls: elevated HR (145.6 ± 7.8 vs. 125.4 ± 4.2 bpm; *p* < 0.013), diminished QRS amplitude (1.1 ± 0.1 vs. 1.3 ± 0.1 mv; *p* < 0.013), abbreviated QT intervals (201.5 ± 8.3 vs. 223.2 ± 5.1 ms; *p* < 0.022), and pronounced ST-segment deviation (0.17 ± 0.02 vs. 0.10 ± 0.01 mv; *p* < 0.001). Hematological correlations demonstrated significant inverse relationships between Hb levels and HR (spearman’s ρ = -0.62; *p* < 0.001) and between serum iron concentrations and ST-segment deviations (ρ = -0.68; *p* < 0.001). Subgroup stratification by anemia severity (Hb <7 vs. ≥7 g/dl) revealed exacerbated tachycardia (168.4 ± 32.1 vs. 132.6 ± 29.5 bpm; *p* < 0.001) and ST abnormalities (0.31 ± 0.12 vs. 0.15 ± 0.1 mv; *p* = 0.003) in severe cases. These findings suggest that IDA-induced myocardial hypoxia and altered ion homeostasis underlie electrophysiological disturbances, manifesting as repolarization anomalies and compensatory tachycardia. Notably, the observed reduction in QRS amplitude diverges from human studies, emphasizing species-specific cardiac adaptations to anemia. The study highlights the clinical utility of ECG monitoring in IDA management to identify early cardiovascular compromise, particularly in settings with limited diagnostic resources. Further research is warranted to establish breed-specific reference intervals and assess ECG normalization post-therapy. By elucidating cardiac manifestations of canine IDA, this work addresses a significant knowledge gap in veterinary cardiology, providing insights to reduce anemia-associated cardiac morbidity through targeted interventions.