Evaluation of Medetomidine–Ketamine–Butorphanol Anesthesia with Atipamezole–Naltrexone Antagonism in Captive Male Guanacos (Lama guanicoe)

Abstract

Seven captive adult male guanacos (Lama guanicoe) weighing 112.0 +/- 10.9 kg (mean +/- standard deviation) were anesthetized with a combination of medetomidine (90.0 +/- 8.8 microg/kg), ketamine (2.7 +/- 0.3 mg/kg), and butorphanol (0.3 +/- 0.03 mg/kg) administered intramuscularly to evaluate its anesthetic and cardiopulmonary effects. Inductions were smooth and rapid, with a mean time to initial effect of 3 +/- 1.5 min and a mean time to recumbency of 5.1 +/- 3.1 min. Anesthesia was predictable, smooth, and characterized by excellent muscle relaxation. Spontaneous ventilation was maintained throughout anesthesia in all animals. Marked bradycardia ranging from 24 to 52 beats/min was noted across all time points for all individuals. Median heart rates decreased during the procedures, but median heart rate, temperature, respiratory rate, and end-tidal carbon dioxide values over the 20 min monitoring period were not significantly different. Mean arterial partial pressure of oxygen (PaO2) on initial sampling was 65.9 +/- 14.8 mm Hg, with six of seven animals exhibiting hypoxemia (PaO2 <80 mm Hg). After oxygen supplementation for 20 min, mean PaO2 values showed statistically significant increases to a mean value of 127.7 +/- 32.4 mm Hg (P = 0.0014). Mean arterial partial pressure of carbon dioxide (PaCO2) showed a significant increase over the monitoring period (P = 0.0004), and mild hypoventilation (PaCO2 >45 mm Hg) was noted in four animals. Mean total duration of procedure time was 23.3 +/- 3.3 min. All guanacos received 0.45 +/- 0.04 mg/kg atipamezole and 2.7 +/- 0.25 mg/kg naltrexone administered intramuscularly for anesthetic antagonism. Recoveries were smooth and uncomplicated. Mean time to sternal recumbency after antagonist administration was 7.7 +/- 4.5 min, and time to successful standing was 12.9 +/- 5.0 min, with all animals standing on first attempt.

Comparison of invasive and oscillometric blood pressure measurement techniques in anesthetized sheep, goats, and cattle

“…,b; Georoff et al. ). If the patient was laterally recumbent, the cuff was positioned on the non‐dependent limb (Prado et al.…”

“…,b; Georoff et al. ). The limb circumference at this point was measured, and a cuff was chosen that was approximately 50% of the circumference of the limb, in congruence with guidelines that the cuff width should be 40–60% of the circumference of the limb (Geddes et al.…”

Maintenance of Genetic Diversity in an Introduced Island Population of Guanacos after Seven Decades and Two Severe Demographic Bottlenecks: Implications for Camelid Conservation

“…For comparison, material suitable for DNA analysis (170 samples) was collected from eight localities throughout southern Patagonia and Staats Island ( Figure 1 , Table 1 ). DNA was extracted: i) from muscle or skin samples from 36 dead animals from Staats Island and Tierra del Fuego (Chile), ii) from blood samples of 34 wild-caught adults following chemical immobilization [43] , [44] at Torres del Paine National Park and Tierra del Fuego (Chile), and iii) from 74 fresh fecal samples from different dung piles at Bosques Petrificado National Parck, San Julian and Monte Leon (Argentina) and Pali-Ayke National Park (Chile). DNA was also obtained opportunistically from liver samples of 26 adult males in Valle Chacabuco, Chile.…”

Comparison of Ketamine-Xylazine, Butorphanol-Azaperone-Medetomidine, and Nalbuphine-Medetomidine-Azaperone for Raccoon (Procyon Lotor) Immobilization

“…This has been tested in several species, such as white-tailed deer 2021). Most studies noted that BAM was effective for immobilization; however, hypoxemia has been noted in guanaco (Lama guanicoe; Georoff et al 2010) and red deer (Cervus elaphus; Wolfe, Fisher, Davis et al 2014), and an insufficient depth of anesthesia was noted for hole drilling for tail transmitter placement in American beavers (Castor canadensis; Roug et al 2018).…”