2026-10-07T23:20:55Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34015068 2026-09-28T15:19:07Z category_1325 portal_316 item_type_3 month_year_09_2026

Table 1_Hematologic follow-up of metamizole-associated Heinz body anemia in dogs.docx Cathrina Richter (25132068) Vera Geisen (16614234) Jelena Palić (14019892) René Dörfelt (13172577) Veterinary Anaesthesiology and Intensive Care dipyrone drug-associated hematotoxicity eccentrocytes erythrocyte hemolysis oxidative stress Introduction<p>Heinz body (HB) anemia is uncommon in dogs. Metamizole is described as a potential trigger in isolated cases.</p>Aim of the study<p>The present study describes the course of metamizole-associated HB anemia in dogs with the development of hematocrit, HBs, and eccentrocytes. In addition, the correlation between HBs, eccentrocytes, hematocrit, and reticulocytes is investigated.</p>Materials and methods<p>In this prospective observational study, 25 dogs with metamizole-associated HB anemia were included. Hematologic examinations and blood smear evaluations for quantification of HBs and eccentrocytes (stained with brilliant cresyl blue and modified Wright's stain) were performed on day 0 and at the control intervals 1–3, 4–6, 7–13, and 14–20 days after discontinuation of metamizole and initiation of antioxidant treatment. Known alternative causes of oxidative erythrocyte damage were excluded. Data were analyzed using Kruskal-Wallis test, Friedman test, and Spearman correlation.</p>Results<p>HB anemia was detected a median of 10 days after initiation of metamizole (median cumulative dose 720 mg/kg). On day 0, HB percentage did not correlate with metamizole dose or hematocrit. The eccentrocyte count did not correlate with metamizole dose, hematocrit, or reticulocyte count. However, a moderate to strong correlation was identified between HB percentage and reticulocyte count (r = 0.630). Median HBs and eccentrocytes decreased from 26.5% and 2.6% on day 0 to 1.3% and 0% on days 14–20, while median hematocrit increased from 24 to 33%. Four dogs received blood transfusions. All patients had at least one concurrent disease. Twenty-one dogs survived and four dogs were euthanized or died.</p>Conclusion<p>In dogs with concurrent disease, metamizole administration may be associated with clinically relevant erythrocyte oxidative damage. Discontinuation of metamizole and initiation of antioxidant therapy were followed by a decrease in HBs and recovery of hematocrit. The use of metamizole in multimorbid dogs should be carefully considered and accompanied by regular hematology controls.</p> 2026-09-28T15:19:07Z Dataset Dataset 10.3389/fvets.2026.1913770.s003 https://figshare.com/articles/dataset/Table_1_Hematologic_follow-up_of_metamizole-associated_Heinz_body_anemia_in_dogs_docx/34015068 CC BY 4.0