Abstract

Data evaluating ultra-potent opioids in okapi (Okapia johnstoni) are limited, with no documented literature in the species informing thiafentanil use. This report retrospectively summarizes its use from seven anesthetic events performed over a 6-wk period on a 1.5-yr-old female okapi being managed for a fetlock injury. A combination (median; range) of butorphanol (0.045; 0.031–0.046 mg/kg), medetomidine (0.037; 0.031–0.037 mg/kg), ketamine (0.553; 0.536–1.071 mg/kg), and thiafentanil (0.0045; 0.0040–0.0046 mg/kg) (BMKT) was administered intramuscularly with the animal in a padded stall. The first two anesthetic events utilized a single dart for anesthetic delivery, while in all other remaining events, BM was administered approximately 10 min prior to KT using a staggered two-dart protocol. Following initial darting, time (median; range) to first effects, (6; 3–7 min) recumbency, (14; 4–20 min) and restraint (16; 6–22 min) were recorded. Induction quality was subjectively assessed as poor (1), fair (2), good (3) or excellent (4). Median induction quality was superior using the two-dart protocol (4) versus a single dart (1.5). Following recumbency, the okapi was intubated and ventilated. Median (range) anesthesia duration (from initial dart to administration of reversal drugs, which included atipamezole and naltrexone) was 81 min (71–124 min). Neither resedation nor renarcotization were observed, and regurgitation did not occur under anesthesia. Both thiafentanil protocols appear suitable for use in okapi. Similar to existing reported carfentanil protocols, the use of a staggered two-dart protocol provided a qualitatively smoother induction owing to the sedation achieved prior to anesthetic drug administration.