Allometric scaling for chemical restraint in greater Rheas (Rhea americana) with Tiletamine and Zolazepam

Abstract

BackgroundChemical restraint is of great importance in the clinical practice of wildlife animals. In such, interspecific allometric scaling proposes pharmacological doses to a wide range of species, based on previously known doses for domestic animals and the target animal’s body mass. The objective was to compare chemical restraint responses in the greater rhea (Rhea americana) with conventional doses of tiletamine/zolazepam, found in the literature for the species, and with doses calculated through interspecific allometric scaling extrapolation. From the Federal University of Piauí, six adult greater rheas (Rhea americana), three males and three females, were randomly selected to be subjects in this research. All six animals were submitted to two chemical restraint protocols with tiletamine and zolazepam, per intramuscular injection in the hind limb. The first protocol was composed of doses found on the literature for the species, while the second protocol used doses calculated by interspecific allometric scaling, with the domestic dog as model animal. Heart and respiratory rates, body temperature, eyelid reflex, digital pinch and metatarsal reflex were registered along with latency and ambulation times.ResultsThe use of interspecific allometric scaling for chemical restraint with the combination tiletamine and zolazepam showed satisfying results, with great similarity to results obtained with conventional doses in Greater rheas.ConclusionsLiterature on chemical restraint and use of tiletamine and zolazepam in rheas is scarce. Chemical restraint is of extreme importance on these animals, due to their aggressive nature and low level of domesticity. This research may further establish the interspecific allometric scaling method as a viable tool for the veterinary physician in formulating anesthetic and chemical restraint protocols for wildlife animals.

Comparison of four chemical restraint protocols in pacas

“…The interspecific allometric scaling method proved to be safe and affective to extrapolate drug doses between different animal species, corroborating data published by others authors KOPROSKI;LANGE, 2009;OSILHEIRE-JUNIOR et al, 2012;POLEZE et al, 2014;CIANCA et al, 2014;PACHALY et al, 2014;PINHEIRO et al, 2014;ANDO et al, 2015).…”