Dynamics of Gastro-Intestinal Strongyle Parasites in a Group of Translocated, Wild-Captured Asiatic Wild Asses in Kazakhstan.

Diana S Gliga,Chris Walzer,Natalia Petrova,Petra Kaczensky,Steffen Zuther,Albert R Salemgareyev,John D C Linnell

doi:10.3389/fvets.2020.598371

Abstract

Asiatic wild ass (Kulan, Equus hemionus) population range and numbers became severely reduced and a reintroduction project is currently aiming to re-establish a population in the Central Steppe of Kazakhstan. Pre-emptive deworming is often recommended for equid translocations but eliminating parasites prior to translocation could cause disruptions in a balanced host-parasite relationship, adding an additional stressor to an already stressful intervention involving capture, transport, and adaptation to a new environment. Following a disease risk assessment, we decided against pre-emptive deworming and focused on monitoring the first group of nine translocated kulan in a large acclimatization enclosure prior to release. Over the 5-month acclimatization period, we regularly collected fecal samples and analyzed the shedding intensity of gastro-intestinal parasite eggs, obtained time budgets through behavioral observations, and visually assessed body condition. We identified strongyles (Strongylinae and Cyathostominae) and pinworms (Oxyuris equi) in fecal samples. All individuals shed strongyle eggs and two of the nine individuals had higher shedding intensities, but rarely reached levels for which deworming is recommended. All kulan appeared healthy throughout the observation period, aggressive interactions were very rare, and time budgets were very similar and dominated by feeding. Our results suggest that in translocation projects where the risk of introducing new parasites is minimal, pre-emptive treatment in wild equids can be replaced with non-invasive monitoring during the acclimatization period. We acknowledge that the small number of kulan, the large size of the enclosure, and the low temperatures during the animals stay in the acclimatization enclosure may all have reduced infestation pressure.

Highlights

Conservation translocations aim at restoring species and ecosystem functioning, but require a careful risk assessment
Strongyles have been previously documented in wild kulan in Mongolia, and in domestic horses in Kazakhstan [7, 34]
The values were lower than those observed in wild kulan in Mongolia [mean: 815, [7]] and in the lower range of values found in other free-ranging wild and feral equids

Summary

Introduction

Conservation translocations aim at restoring species and ecosystem functioning, but require a careful risk assessment. Gastro-intestinal parasites, strongylids, are common in domestic and wild equids [6, 7]. High stress management interventions such as capture and transport could weaken the immune system [12] and confinement to an adaptation enclosure over an extended time with conspecifics could result in the exposure to infectious parasite due to the accumulation of feces [13], both of which could result in unusually high parasite burdens. Fecal examination of endoparasites and treatment are generally recommended for equid reintroductions [14], but eliminating parasites prior to translocation could cause disruptions in a balanced host-parasite relationship, adding an additional stressor to an already stressful intervention involving capture, handling, transport, and adaptation to a new environment [12, 15, 16]

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