Physical capture and chemical immobilization procedures for a mammal with singular anatomy: the giant anteater (Myrmecophaga tridactyla)

The giant anteater ( Myrmecophaga tridactyla ), the largest representative of the xenarthrans, is listed as Vulnerable-IUCN. Their unique anatomy and physiological characteristics, such as relatively low basal metabolic rates, make xenarthrans challenging to anesthetize and equip with tracking devices. This study evaluates and describes physical capture and chemical immobilization protocols for field conditions that enable the harnessing of free-ranging giant anteaters. A total of 51 wild giant anteaters were physically captured, and chemical immobilization was performed applying the combination protocol (BDM), butorphanol tartrate, detomidine hydrochloride, and midazolam hydrochloride, each at 0.1 mg/kg. Whenever extra time was necessary, supplementary doses of BDM were used (0.03 mg/kg of butorphanol, 0.03 mg/kg of detomidine, and 0.03 mg/kg of midazolam). Vital signs were monitored during anesthesia every 10 min. All individuals received the antagonist combination NYF: naloxone hydrochloride (0.02 mg/kg), yohimbine hydrochloride (0.125 mg/kg), and flumazenil (0.01 mg/kg). Average rectal temperature was 34.5 ± 2.52 °C, heart rate/min 43.47 ± 7.39, respiratory rate 8.49 ± 2.79, and oxygen saturation values (SpO2%) 90.1 ± 4.38. BDM protocol was considered satisfactory and provided enough time to complete the procedures. The total chemical immobilization time was 85.5 ± 16.8 min. This protocol provided rapid, smooth inductions, and a wide margin of safety. Recovery time varied according administration method lasting 2.55 ± 1.33 to 12 ± 5.39 min intravenous or intramuscular, respectively. Physical capture method and the chemical immobilization protocol were considered efficient, safe, highly feasible, and can be completely antagonized, promoting smooth and rapid recoveries.