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

Abstract OBJECTIVE To demonstrate the efficacy of potassium chloride (KCl) for low-residue euthanasia anesthetized pinnipeds in field settings which carcass retrieval disposal is not feasible. ANIMALS Stranded, free-ranging California sea lions (CSLs; Zalophus californianus ; n = 17) and northern elephant seals (NESs; Mirounga angustirostris 6) with life-threatening injury or disease between May August 2020. PROCEDURES Each animal was then received a lethal dose KCl solution administered by IV intracardiac injection. The effective dose; durations to cardiac arrest, respiratory pupil dilation; presence absence agonal breaths, muscle fasciculations, skeletal movements were recorded. RESULTS Mean 207.4 mg/kg (94.3 mg/lb) 17 CSLs 209.1 (95.0 5 6 NESs (1 outlier NES excluded). range duration from beginning injection arrest 0 minutes, dilation minutes. Muscle movements, breaths observed both species during after administration. CONCLUSIONS AND CLINICAL RELEVANCE use provides an effective, method NESs. Our recommended these 250 mg KCl/kg (113.6 KCl/lb) delivered Compared barbiturate overdose, reduces potential secondary intoxication scavengers appropriate scenarios cannot be retrieved disposal. ( J Am Vet Med Assoc 2021;259:197–201)