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Vdb Morkel P.,Frankfurt Zoological Society | Radcliffe R.W.,Foundation Medicine | Radcliffe R.W.,Cornell University | Jago M.,Namibia Ministry of Environment and Tourism | And 7 more authors.
Journal of Wildlife Diseases | Year: 2010

Posture, ventilation, and acid-base balance using auricular venous blood values (pH, lactate, base excess [BE], HCO3 -, PO 2, SO2, and PCO2), oxygen saturation of hemoglobin (SpO2), and end-tidal carbon dioxide (P ETCO2) were compared between sternal (STE) and lateral (LAT) recumbency in free-ranging black rhinoceros (Diceros bicornis bicornis) receiving oxygen insufflation. Data are reported as median, minimum, and maximum (median [minimum, maximum]). Thirty-six desert-adapted black rhinoceros (20 male, 16 female; age 8 [1.5, 33] yr) were immobilized in Namibia in March and April of 2008, from a helicopter, by remote intramuscular injection with etorphine HCl, azaperone, and hyaluronidase. Time from darting to recumbency was 6.0 (3, 15.5) min. Data were organized into two sampling periods: sample period 1 (P1, collected within 020 min postdarting; 13 [6.5, 19] min) and sample period 2 (P2, collected between 2040 min postdarting; 32 [22.3, 39] min). All animals were acidemic (pH 7.24 [7.07, 7.32]) and hypoxemic (PO2 51 [38, 95.2]; SO2 78 [64, 96] mmHg) after capture. Lactate at P1 was 7.2 (3.2, 16.8) mmol/1 and decreased (P=0.01) to 4.6 (1.2, 10.9) mmol/1 at P2. At P2, lactate was less (P=0.06) in LAT 3.5 (1.2, 8.6) mmol/1 than in STE posture 7.4 (3.1, 10.9) mmol/1. In P2, PO2, SO2, and SpO2 were higher (P=0.02, 0.10, and 0.01, respectively) in STE than in LAT. End-tidal carbon dioxide in LAT was 38 (26, 47) mmHg and increased (P<0.001) rapidly to 48 (37, 55) mmHg when animals were moved into STE; no corresponding change in PCO2 was observed. These preliminary findings suggest that STE posture in recumbent black rhinoceros reduces dead-space ventilation and improves oxygenation. Lateral posture was associated with lower blood lactate, quicker lactate recovery, or both. It is possible that the posture of recumbent rhinoceros after capture affects lactate accumulation and clearance, or both, and procedures should consider positioning in order to enhance perfusion. © Wildlife Disease Association 2010.

Miller M.,Palm Beach Zoo | Jago M.,Namibia Ministry of Environment and Tourism | Radcliffe R.,Cornell University | Morkel P.B.,Frankfurt Zoological Society | And 6 more authors.
Journal of Wildlife Diseases | Year: 2012

Hypoglycemia (glucose,65 mg/dl) was detected in 21 of 28 immobilized freeranging black rhinoceroses (Diceros bicornis). At repeat sampling 25 min later, only 6 of 28 were hypoglycemic (P<0.05). Lactate was significantly higher (P<0.0001) early in immobilization. Hypoglycemia and elevated lactate may increase risk of anesthetic complications and postrecovery problems. © Wildlife Disease Association 2012.

Morkel P.V.,Frankfurt Zoological Society | Miller M.,Palm Beach Zoo | Jago M.,Namibia Ministry of Environment and Tourism | Radcliffe R.W.,Cornell University | And 6 more authors.
Journal of Zoo and Wildlife Medicine | Year: 2012

Control of body temperature is critical to a successful anesthetic outcome, particularly during field immobilization of wild animals. Hyperthermia associated with exertion can lead to serious and potentially life-threatening complications such as organ damage (including myopathy) and death. Methods for monitoring core body temperature must accurately reflect the physiologic status of the animal in order for interventions to be effective. The goal of this preliminary study was to compare serial rectal and muscle temperatures in field-immobilized black rhinoceros (Diceros bicornis) and evaluate a possible association. Twenty-four free-ranging black rhinoceros were immobilized between February and March of 2010 in Ethosha National Park, Namibia. Pairwise comparisons showed a correlation of 0.73 (95% CI; -0.70-0.75) between rectal and muscle temperature measurements. Results from a multivariable model indicate that muscle temperature readings were, on average, 0.46°C (95% CI; -0.36-0.57°C) higher than rectal temperatures while adjusting for repeated measurements on the same rhinoceros, effect of duration of immobilization, and effect of ambient temperature on rhinoceroses' temperature readings. As immobilization time increased, muscle and rectal temperature values within an individual rhinoceros tended to equilibrate. The overall temperatures decreased by an average of 0.00059°C/min (95% CI; -0.0047 to -0.0035°C/min; P = 0.779). As the ambient temperature at time of immobilization increased by 1°C, the average rhinoceros temperature increased by 0.09°C (95% CI; 0.060.11°C, P < 0.0001). Higher body temperature creates a potential for cellular damage leading to complications that include myopathy. Methods for monitoring rectal, muscle, and ambient temperatures should be incorporated into anesthetic monitoring protocols for large ungulates, particularly under field conditions. Copyright © 2012 by American Association of Zoo Veterinarians.

Radcliffe R.W.,Cornell University | Morkel P.,Private Consultant | Jago M.,Namibia Ministry of Environment and Tourism | Taft A.A.,Georgia Regents University | And 6 more authors.
Journal of Zoo and Wildlife Medicine | Year: 2014

It was observed previously that end-expired carbon dioxide (PÉCO2) decreased when immobilized black rhinoceroses (Diceros bicornis) were moved from sternal to lateral recumbency. These experiments were designed to test whether greater alveolar ventilation or greater pulmonary dead space in lateral recumbency explains this postural difference in PÉCO2. Twenty-one (9 male, 12 female; 15 3.5-26 yr old) wild black rhinoceroses were immobilized with etorphine and azaperone and positioned in either sternal or lateral recumbency. All rhinoceroses were hypoxemic and had lactic and respiratory acidemia. The animals in lateral recumbency were more acidemic, had higher lactate, and lower arterial oxygen that those in sternal recumbency; however, arterial carbon dioxide was similar between groups. Both PÉCO2 and mixed expired carbon dioxide pressure were lower in lateral than sternal recumbency. Although there was no difference in tidal volume or arterial carbon dioxide, both the breathing rate and minute ventilation were greater in lateral recumbency. The physiologic dead space ratio and dead space volume were approximately two times larger in lateral recumbency; hence, the decrease in PÉCO2 in lateral recumbency can be attributed to increased dead space ventilation not increased alveolar ventilation. Positioning immobilized rhinoceroses in lateral recumbency does not confer any advantage over sternal in terms of ventilation, and the increase in minute ventilation in lateral recumbency can be considered an energetic waste. Although arterial oxygen was superior in sternal recumbency, further studies that measure oxygen delivery (e.g., to the muscles of locomotion) are warranted before advice regarding the optimal position for immobilized rhinoceroses can be given with confidence. © 2014 by American Association of Zoo Veterinarians.

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