Effect of Intracoelomic Propofol in White's Tree Frogs, Pelodryas caerulea
Assoc Reptilian Amphibian Vet 9[3]:7-8 Fall'99 In My Experience 13 Refs

The goal of this study was to determine if intracoelomic propofol would be absorbed and distributed in White's tree frog, Pelodryas (Litoria) caerulea, in a manner that provides anesthesia. This is the first report of propofol use in an amphibian. Three wild-caught, adult Indonesian White's tree frogs were used in this study. Food was withheld from the frogs for at least 24 hours prior to anesthesia. As intravenous access in an awake frog is problematic, intracoelomic (ICe) was used as the route of administration for a single bolus of propofol. Propofol was administered at a low dosage of 9.5 mg/kg ICe to a 42.0 g frog, an intermediate dosage of 30 mg/kg ICe to a 59.5 g frog, and a high dosage of 53 mg/kg ICe to the 39.7 g frog. The low dose and intermediate dose frogs showed immediate ventral erythema. Time to loss of muscle tone was 17 minutes for the low dose, six minutes for the intermediate dose, and one minute for the high dose. Time to maximum effect was 19 minutes for low dose, eight minutes for intermediate dose, and one minute for the high dose. The maximum effect of propofol was loss of righting response at 9.5 mg/kg ICe, loss of respiratory movements at 30 mg/kg ICe, and loss of visible cardiac movements within one minute at 53 mg/kg ICe. The low-dose and intermediate-dose frogs were recovered to an alert posture within four hours and were completely recovered within 16 hours. The high-dose frog was presumed dead at one minute due to absence of visible cardiac movement; but it was not declared dead until 16 hours from induction at which time the other frogs were fully recovered. Propofol at 9.5 mg/kg ICe may be useful for sedating White's tree frogs for diagnostic procedures while a higher dosage of 30 mg/kg Ice may provide adequate anesthesia for invasive techniques such as surgery. 53 mg/kg ICe resulted in excessively deep anesthesia within one minute and the frog subsequently died [The frog had been a candidate for euthanasia due to intractable nematodiasis and there were multiple verminous cysts in the skeletal muscle and visceral organs at necropsy]. It is possible that the organ pathology affected the anesthesia in this frog and may have contributed to its death. It is unknown if 53 mg/kg ICe would be fatal in other specimens; nevertheless, a propofol dose of 53 mg/kg ICe is not recommended in this species for survival procedures.