{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T22:56:04Z","timestamp":1791240964408,"version":"4.1.0"},"reference-count":18,"publisher":"American Association of Zoo Veterinarians","issue":"2","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Zoo and Wildlife Medicine"],"published-print":{"date-parts":[[2025,6,5]]},"abstract":"<jats:p>Immersion bath in high doses of tricaine methanesulfonate (MS-222) and eugenol is a common euthanasia method for fish, causing rapid cessation of opercular movements. However, in previous studies where cardiac contractions persisted, despite dosages of MS-222 as high as 1000 mg\/L, the hypothesis was advanced that apnea could prevent effective euthanasia. The objective of the study was to determine if continuous topical delivery (CTD) over the gills of MS-222 or clove oil (CO) would result in cardiac arrest at 60 minutes, without recovery after placement in fresh water for an additional 60-minute period. Thirty-six juvenile red head Tapajos eartheaters (Geophagus pyrocephalus) were randomly divided into six experimental groups (six fish\/group, concentration of the anesthetics indicated in mg\/L): (1) Bath MS 500; (2) CTD MS 500; (3) Bath CO 500; (4) CTD CO 500; (5) Bath CO 1000; (6) CTD CO 1000. The proportion of fish with a heartbeat at 60 minutes and the mean time to cardiac arrest (P &lt; 0.001) were significantly different among groups. At 60 minutes, 6\/6 and 5\/6 of fish in the Bath CO 1000 group and the Bath CO 500 group experienced cardiac arrest, respectively, while only 1\/6 and 3\/6 of fish in the CTD CO 500 group and the CTD CO 1000, respectively, did. By 120 minutes, all fish except two fish in the CTD MS 500 group had undergone cardiac arrest. In contrast to our hypothesis, mean time to cardiac arrest occurred faster in immersion bath than in CTD at both concentrations of CO (P \u2264 0.022).<\/jats:p>","DOI":"10.1638\/2025-0001","type":"journal-article","created":{"date-parts":[[2025,6,5]],"date-time":"2025-06-05T04:39:08Z","timestamp":1749098348000},"page":"303-310","source":"Crossref","is-referenced-by-count":0,"title":["EUTHANASIA BY CONTINUOUS TOPICAL DELIVERY OF CLOVE OIL OVER THE GILLS RESULTS IN DELAYED CARDIAC ARREST IN COMPARISON TO IMMERSION BATH IN JUVENILE RED HEAD TAPAJOS EARTHEATERS (GEOPHAGUS PYROCEPHALUS)"],"prefix":"10.1638","volume":"56","author":[{"given":"Lydie-Amy","family":"Leclerc","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claire","family":"Vergneau-Grosset","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tristan","family":"Juette","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"St\u00e9phane","family":"Lair","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Karine","family":"B\u00e9land","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1213","reference":[{"key":"15","doi-asserted-by":"crossref","unstructured":"M Matthews  and ZM Varga  \"ILAR J.\"  53, \"Anesthesia and euthanasia in zebrafish.\" 192 (2012)","DOI":"10.1093\/ilar.53.2.192"},{"key":"2","doi-asserted-by":"crossref","unstructured":"N Ayala-Soldado, R Mora-Medina, AJ Lora-Benitez, et al.  \"Lab Anim.\"  57, \"Comparative study of tricaine methanesulfonate (MS-222) and eugenol as euthanasia agents in zebrafish (Danio rerio) as an experimental model.\" 236 (2023)","DOI":"10.1177\/00236772221143939"},{"key":"4","doi-asserted-by":"crossref","unstructured":"S Bradley, S Sparrow, LJ Rowden, et al.  \"J Zoo Wildl Med.\"  52, \"Use of tricaine methanesulfonate, clove oil and 2-phenoxyethanol for immersion euthanasia of Unga cichlids (Sarotherodon linellii).\" 893 (2021)","DOI":"10.1638\/2020-0165"},{"key":"6","doi-asserted-by":"crossref","unstructured":"KM Carter, CM Woodley, RS Brown,  \"Rev Fish Biol Fisheries.\"  21, \"A review of tricaine methanesulfonate for anesthesia of fish.\" 51 (2011)","DOI":"10.1007\/s11160-010-9188-0"},{"key":"8","doi-asserted-by":"crossref","unstructured":"AL Day, S Liu, CP Kozlowski, et al.  \"J Zoo Wildl Med.\"  54, \"Evaluation of plasma cortisol and lactate in koi (Cyprinus carpio) euthanized by immersion in tricaine methanesulfonate, clove oil, or carbon dioxide gas dissolved in water.\" 825 (2023)","DOI":"10.1638\/2022-0109"},{"key":"9","unstructured":"KE Ferguson  and JA Balko  \"Annual International Association for Aquatic Animal Medicine (IAAAM) conference, virtual conference.\"  \"Continuous topical delivery of tricaine methanesulfonate is effective for euthanasia of goldfish (Carassius auratus).\" 2021"},{"key":"10","doi-asserted-by":"crossref","unstructured":"AC Heniff  and JA Balko  \"J Zoo Wildl Med.\"  54, \"Potassium chloride administered via four routes for euthanasia of anesthetized goldfish (Carassius auratus).\" 435 (2023)","DOI":"10.1638\/2022-0130"},{"key":"11","doi-asserted-by":"crossref","unstructured":"K Herrmann, F Schumacher, W Engst, et al.  \"Carcinogenesis.\"  34, \"Abundance of DNA adducts of methyleugenol, a rodent hepatocarcinogen, in human liver samples.\" 1025 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surgeonfish (Paracanthurus hepatus).\" 137 (2023)","DOI":"10.1638\/2022-0022"},{"key":"3","doi-asserted-by":"crossref","unstructured":"JA Balko, A Oda, LP Posner,  \"J Am Vet Med Assoc.\"  252, \"Use of tricaine methanesulfonate or propofol for immersion euthanasia of goldfish (Carassius auratus).\" 1555 (2018)","DOI":"10.2460\/javma.252.12.1555"},{"key":"1","unstructured":"\"Guidelines for the Euthanasia of Animals: 2020 Edition.\"  (2020)"},{"key":"14","doi-asserted-by":"crossref","unstructured":"MM Louis, EL Houck, GA Lewbart, et al.  \"J Zoo Wildl Med.\"  51, \"Evaluation of potassium chloride administered via three routes for euthanasia of anesthetized koi (Cyprinus carpio).\" 485 (2020)","DOI":"10.1638\/2019-0207"},{"key":"5","doi-asserted-by":"crossref","unstructured":"S Bradley, S Sparrow, LJ Rowden, et al.  \"J Zoo Wildl Med.\"  53, \"Comparison of three concentrations of Aqua-Sed\u2122 for immersion euthanasia of butterfly splitfin (Ameca splendens).\" 241 (2022)","DOI":"10.1638\/2021-0059"},{"key":"17","doi-asserted-by":"crossref","unstructured":"C Perret-Thiry, J Raulic, C Vergneau-Grosset,  \"J Am Vet Med Assoc.\"  260, \"Evaluation of prolonged immersion in tricaine methanesulfonate for juvenile goldfish (Carassius auratus) euthanasia.\" 911 (2022)","DOI":"10.2460\/javma.21.09.0416"},{"key":"7","unstructured":"DJ Davis, J Klug, M Hankins, et al.  \"J Am Assoc Lab Anim Sci.\"  54, \"Effects of clove oil as a euthanasia agent on blood collection efficiency and serum cortisol levels in Danio rerio.\" 564 (2015)"}],"container-title":["Journal of Zoo and Wildlife Medicine"],"original-title":[],"deposited":{"date-parts":[[2026,10,5]],"date-time":"2026-10-05T22:29:34Z","timestamp":1791239374000},"score":1,"resource":{"primary":{"URL":"https:\/\/bioone.org\/journals\/journal-of-zoo-and-wildlife-medicine\/volume-56\/issue-2\/2025-0001\/EUTHANASIA-BY-CONTINUOUS-TOPICAL-DELIVERY-OF-CLOVE-OIL-OVER-THE\/10.1638\/2025-0001.full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,5]]},"references-count":18,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2025,6,1]]}},"URL":"https:\/\/doi.org\/10.1638\/2025-0001","relation":{},"ISSN":["1042-7260","1937-2825"],"issn-type":[{"value":"1042-7260","type":"print"},{"value":"1937-2825","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,6,5]]}}}