{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T15:57:51Z","timestamp":1790611071756,"version":"4.1.0"},"reference-count":46,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T00:00:00Z","timestamp":1790553600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Vet. Sci."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>Heinz body (HB) anemia is uncommon in dogs. Metamizole is described as a potential trigger in isolated cases.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Aim of the study<\/jats:title>\n                    <jats: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.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and methods<\/jats:title>\n                    <jats: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\u20133, 4\u20136, 7\u201313, and 14\u201320 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.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      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 (\n                      <jats:italic>r<\/jats:italic>\n                      = 0.630). Median HBs and eccentrocytes decreased from 26.5% and 2.6% on day 0 to 1.3% and 0% on days 14\u201320, 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.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion<\/jats:title>\n                    <jats: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.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/fvets.2026.1913770","type":"journal-article","created":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T15:27:42Z","timestamp":1790609262000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Hematologic follow-up of metamizole-associated Heinz body anemia in dogs"],"prefix":"10.3389","volume":"13","author":[{"given":"Cathrina","family":"Richter","sequence":"first","affiliation":[{"name":"LMU Small Animal Clinic, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universit\u00e4t in Munich","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vera","family":"Geisen","sequence":"additional","affiliation":[{"name":"LMU Small Animal Clinic, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universit\u00e4t in Munich","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jelena","family":"Pali\u0107","sequence":"additional","affiliation":[{"name":"Division of IDEXX Laboratories, Vet Med Labor GmbH","place":["Kornwestheim, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ren\u00e9","family":"D\u00f6rfelt","sequence":"additional","affiliation":[{"name":"LMU Small Animal Clinic, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-Universit\u00e4t in Munich","place":["Munich, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,28]]},"reference":[{"key":"B1","article-title":"Anemia, Erythrocytosis","volume-title":"Textbook of Veterinary Internal Medicine: Diseases of the Dog and the Cat","author":"Stokol","year":"2017"},{"key":"B2","doi-asserted-by":"publisher","first-page":"885","DOI":"10.1182\/blood.V25.6.885.885","article-title":"Heinz body anemia\u2014an ultrastructural study. 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