Comparison of injectable anesthetic combinations in free-ranging two-toed sloths in French guiana.
Immobilization was studied in 202 free-ranging two-toed sloths (Choloepus didactylus). All the sloths were in good condition with a body weight > 2 kg, and were anesthetized for a variety of minor clinical procedures. Intramuscular anesthetic combinations included 0.1 mg/kg acepromazine + 10 mg/kg ketamine (A/K, n = 30), 1 mg/kg xylazine + 10 mg/kg ketamine (X/K, n = 89), 10 mg/kg tiletamine/zolazepam (T/Z, n = 37), and 0.04 mg/kg medetomidine + 3 mg/kg ketamine (M/K, n = 46) antagonized by 0.2 mg/kg atipamezole. The animals were quiet during the induction stage and complete recumbency was reached in (mean +/- SD) 2.5 +/- 2.0 min with A/K, 2.7 +/- 1.7 min with X/K, 1.8 +/- 0.6 min with T/Z, and 2.5 +/- 5 with M/K. Utilization of A/K was not satisfactory because of poor anesthetic level and lack of muscle relaxation. T/Z induced immobilization was characterized by deep anesthesia and good myorelaxation, but often was associated with irregular respiration and low relative oxyhemoglobin saturation values (SpO2). Ketamine in combination with alpha2-agonists, xylazine or medetomidine, provided suitable anesthesia, with good to excellent muscular relaxation, good analgesia, high SpO2 values, moderate bradycardia, but strong bradypnea with medetomidine. Anesthesia with M/K was reversed after 41.6 min of immobilization with atipamezole. Calm recoveries were obtained and the animals were able to hang up after 10.0 +/- 7.9 min. The first signs of arousal were observed within an average of 43 to 51 min after the injection of the three other combinations. Recoveries from X/K immobilization were quiet; sloths held on after 34 min. With T/Z, recovery duration was long and very irregular at 76.7 +/- 31.3 min, some animals required 3 hr before being able to hang up. Finally, ketamine in association with an alpha2-agonist appeared to give the best chemical immobilization in wild two-toed sloths for 40 min procedures including minor surgery.
EDF/CNEH, Le Bourget-du-Lac, France.
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I
Vogel
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de Thoisy
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JC
Vié
D000075:Acepromazine / Q000008:administration & dosage / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D018712:Analgesics, Non-Narcotic / Q000008:administration & dosage / Q000494:pharmacology; D000758:Anesthesia / Q000662:veterinary*; D019162:Anesthetics, Combined / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D000835:Animals, Wild / Q000502:physiology*; D001831:Body Temperature / Q000187:drug effects; D005260:Female; D005616:French Guiana; D006339:Heart Rate / Q000187:drug effects; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology; D007093:Imidazoles / Q000008:administration & dosage / Q000494:pharmacology; D007103:Immobilization; D007273:Injections, Intramuscular / Q000662:veterinary; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D020926:Medetomidine; D009126:Muscle Relaxation / Q000187:drug effects; D010108:Oxyhemoglobins / Q000032:analysis / Q000187:drug effects; D012119:Respiration / Q000187:drug effects; D012896:Sloths / Q000502:physiology*; D013992:Tiletamine / Q000008:administration & dosage / Q000494:pharmacology; D014991:Xylazine / Q000008:administration & dosage / Q000494:pharmacology; D015041:Zolazepam / Q000008:administration & dosage / Q000494:pharmacology
D000317:Adrenergic alpha-Antagonists; D018712:Analgesics, Non-Narcotic; D019162:Anesthetics, Combined; D006993:Hypnotics and Sedatives; D007093:Imidazoles; D010108:Oxyhemoglobins; C050701:atipamezole; D014991:Xylazine; D013992:Tiletamine; D000075:Acepromazine; D007649:Ketamine; D015041:Zolazepam; D020926:Medetomidine