Evaluation of Potassium Chloride Administered via Three Routes for Euthanasia of Anesthetized Koi ( Cyprinus Carpio )

Use of potassium chloride for low-residue euthanasia of anesthetized California sea lions (Zalophus californianus) and northern elephant seals (Mirounga angustirostris) with life-threatening injury or disease

“…This dose is higher than the lethal dose of 75 to 150 mg KCl/kg (34.1 to 68.2 mg KCl/lb) recommended across taxa. 3 Louis et al 9 showed that 10 mEq K + /kg (4.5 mEq K + /lb) administered IC is lethal in anesthetized koi but did not evaluate lower doses. Similarly, Raghav et al 10 indicated that a dose of 3 or 10 mEq K + /kg (1.4 or 4.5 mEq K + /lb) was effective for euthanasia in psittacine birds but that 10 mEq K + /kg resulted in more rapid death.…”

“…Potassium chloride is a recognized euthanasia agent in anesthetized cattle 7 and other domestic large animals. 3 It has been evaluated for efficacy in mice, 8 koi, 9 psittacines, 10 moon jellyfish, 11 American lobsters, 12 and giant cockroaches. 13 Lethal administration of KCl after anesthesia is recommended by the National Oceanic and Atmospheric Administration for euthanasia of stranded cetaceans in some circumstances, 14 has been described for euthanasia of large cetaceans, 6,15 and is an accepted protocol for euthanasia at TMMC.…”

Potassium Chloride Administered via Four Routes for Euthanasia of Anesthetized Goldfish (Carassius Auratus)

“…KCl doses were chosen based on the results of a prior study in koi. 18 Injectable and T doses were calculated using the obtained body weights, and volumes were rounded to the nearest 0.01 ml. A single investigator (ACH) performed all treatments.…”

“…9,11–13,29,30 Even fewer studies have been conducted in those species more commonly encountered in zoos, aquaria, or clinical practice, and these have included koi ( Cyprinus carpio ), Unga cichlids ( Sarotherodon linellii ), goldfish ( Carassius auratus ), butterfly splitfins ( Ameca splendens ), and a limited variety of ornamental fishes. 4,7,8,18,22,31 Given the frequency of euthanasia in fish and the paucity of evidence-based data, further refinement of fish euthanasia methods is warranted.…”

“…3,5,6,15,19,20,24,25 A single study in our laboratory has also investigated KCl euthanasia in a fish species: koi. 18 This study determined that intracardiac injection (IC) of KCl at 10 mEq/kg was effective for euthanasia of anesthetized koi; however, equivalent doses of KCl administered via intracoelomic injection (ICe) or via bilateral topical instillment over the gill filaments (T) were ineffective. 18 Although the latter two routes of administration were ineffective in koi at 10 mEq/kg, evaluating these techniques using higher doses, other fish species, or both is warranted.…”