Objective—To determine ECG and echocardiographic measurements in healthy anesthetized Grevy's zebras (Equus grevyi).
Animals—20 healthy zebras.
Procedures—Auscultation, base-apex ECG, and echocardiography were performed on anesthetized zebras.
Results—Low-grade systolic murmurs were detected in the left basilar region in 4 of 20 zebras. Evaluation of ECGs from 19 zebras revealed sinus rhythm with a predominantly negative QRS complex and a mean ± SD heart rate of 67 ± 10 beats/min. Echocardiograms of sufficient image quality were obtained for 16 zebras. Interventricular septal thickness in diastole, left ventricular chamber in diastole and systole, left atrial diameter, and left ventricular mass were significantly and moderately correlated with estimated body weight (r values ranged from 0.650 to 0.884). Detectable swirling of blood in the right and sometimes the left ventricles was detected in 9 of 16 zebras, whereas physiologic regurgitation of blood was detected for the aortic valve in 3 zebras, pulmonary valve in 2 zebras, mitral valve in 2 zebras, and tricuspid valve in 1 zebra.
Conclusions and Clinical Relevance—Results of this study provide reference information for use in the cardiac evaluation of anesthetized Grevy's zebras.
Objective—To evaluate the efficacy and safety of a combination of dexmedetomidine, butorphanol, and midazolam administered IM for anesthesia in captive Asian small-clawed otters (Aonyx cinereus) and to compare this combination with a combination of ketamine and midazolam.
Design—Prospective crossover study.
Animals—10 captive Asian small-clawed otters.
Procedures—A combination of either dexmedetomidine (0.03 mg/kg [0.014 mg/lb]), butorphanol (0.2 mg/kg [0.091 mg/lb]), and midazolam (0.15 mg/kg [0.068 mg/lb]) or ketamine (10.1 mg/kg [4.59 mg/lb]) and midazolam (0.3 mg/kg [0.14 mg/lb]) was administered IM to otters for immobilization to allow scheduled wellness examinations. Otters were intubated and administered 100% oxygen during the examination. Anesthesia was supplemented with isoflurane in oxygen if necessary. Routine medical procedures, including blood collection, radiography, echocardiography, dental scaling, vaccinations, and contraception administration, were performed as indicated during the immobilization. Physiologic, clinicopathologic, and anesthetic variables were recorded and compared. Otters given dexmedetomidine-butorphanol-midazolam were administered atipamezole (0.2 mg/kg [0.091 mg/lb]), naltrexone (0.6 mg/kg [0.27 mg/lb]), and flumazenil (0.05 mg/kg [0.023 mg/lb]) IM at the completion of the examination.
Results—The need for and duration of isoflurane administration were greater for ketamine-midazolam anesthesia, compared with dexmedetomidine-butorphanol-midazolam anesthesia. Recoveries were shorter and subjectively smoother with dexmedetomidine-butorphanol-midazolam. Heart rates were significantly higher during ketamine-midazolam anesthesia. Regardless of protocol, all otters developed hypothermia and hypercapnia during anesthesia.
Conclusions and Clinical Relevance—Both protocols were safe and effective for this species, but the reversible nature of dexmedetomidine-butorphanol-midazolam resulted in more rapid recoveries than did ketamine-midazolam. Otters anesthetized with ketamine-midazolam may require additional anesthetic medications for routine examinations, and assisted ventilation and thermal support may be of benefit with either protocol.