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  • Author: T. Zharkikh x
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Strongylid Community Structure of the Przewalski's Horses (Equus ferus Przewalskii) from the Biosphere Reserve "Askania-Nova", Ukraine

Species composition and the structure of strongylid community of the Przewalski's horse (Equus ferus przewalskii Poljakov, 1881) semi-free population at the "Askania-Nova" Biosphere Reserve were studied by the in vivo method of diagnostic deworming. After deworming of 24 adult Przewalski's horses by the anthelmintic "Univerm" (0.2% aversectin C, Russia), 25,815 strongylid specimens were collected and identified. Thirty-one strongylid species of 12 genera were found including 6 species of the subfamily Strongylinae and 25 — of Cyathostominae. Nine to 18 strongylid species (average 14.5 ± 2.5) were found per horse. Cyathostomes (Cyathostominae) dominated in the Przewalski's horse strongylid community: 9 species (Cyathostomum catinatum, C. pateratum, Cylicocyclus nassatus, C. insigne, C. leptostomum, C. ashworthi, Cylicostephanus longibursatus, C. goldi and C. minutus) were found in more than 80% of horses examined and composed 94.1% of the total number of strongylid collected. Strongyles (Strongylinae) were found in 100% of the E. ferus przewalskii examined; prevalence of separate species was from 4.2% to 58.3%. The general structure of the strongylid community was multimodal with dominant (9 species), subdominant (4), background (4) and rare (14) species. The list of strongylid species found in the Przewalski'si horses in Ukraine was enlarged to 37 species.

Dynamics of Infection with Strongylidae of the Przewalski Horse (Equus Przewalskii) Population in the Chernobyl Exclusion Zone

Dynamics of Infection with Strongylidae of the Przewalski Horse (Equus przewalskii) Population in the Chernobyl Exclusion Zone. Zvegintsova N. S., Zharkikh T. L., Yasynetska N. I. — In 1998 and in 1999, several Przewalski horses (PH) from the Reserve Askania Nova were transferred to the Chernobyl Exclusion Zone (CEZ), a free-roaming breeding population was therefore established. Parasitological monitoring of the population was carried out between 1998 and 2006. Before the transportation, PHs were dewormed with Albendazole. On arrival, the PHs were placed in large pasture enclosures for acclimatization, where they were kept between a few weeks and eight months before releasing into the wild. Besides PHs, some domestic working horses were kept in the enclosures. After transportation to CEZ, the level of infection with intestinal helminths in PHs increased. Probably, it was due to the following factors: 1) larvae of helminthes, which survived in intestines after deworming, developed, 2) the pasture in acclimatization enclosures was contaminated with parasites, as PHs shared the enclosures with domestic horses. Over the first three years, the prevalence of Strongylidae were 98.8%, the mean intensities varied from 248.0 ± 51.3 to 612.0 ± 278.2 eggs per gram faeces (epg). A mean intensity in bachelor males was higher than in members of harem groups, as the bachelors had closer contacts with domestic horses. After domestic horses had been transferred outside of CEZ in 2001, the overall intensity in PHs has progressively decreased. During 2004-2006, the mean intensity became stable with range 80.9 ± 25.5 to 138.9 ± 33.2 epg, with prevalence of 93.1%. In 3.5% of faecal samples, Parascaris equorum (Ascarididae) were found; a mean intensity was 29.0 ± 10.7 epg. A few eggs of Anoplocephala perfoliata (Anoplocephalidae) were found in three samples only. Due to negligible contamination of pastures excluded from farming industry long ago, there are comparatively low levels of infection in the free-roaming PHs. The present level of infection is considered harmless to the horses as clinical symptoms of helminthoses were never noticed.

Abstract

The Przewalski’s horse (Equus ferus przewalskii, Poljakov, 1881) is an endangered subspecies of wild horses (Equus ferus) native to steppes of Central Asia. In 2015, the Program of Establishing of a Semi-Free Population of the Przewalski’s Horse in the Orenburg Reserve was launched by FGFI “Orenburg Reserves”. The first group of 6 Przewalski’s horses (2 males and 4 females) born in the semi-reserve Le Villaret, France, was transported to the Orenburg Reserve. Th e aim of this work was to investigate the species composition of the intestinal parasite community and to monitor the dynamics of the parasite infection of the newly established Przewalski’s horse population. The level of infection by gastrointestinal parasites within the horses was examined by the McMaster method. Gastrointestinal parasites were collected in vivo after deworming of the horses with macrocyclic lactone drug “Univerm” (0.2 % aversectin C, PharmBioMed, Russia). Totally, 20 species of parasites were found: 19 species of nematodes (species of the family Strongylidae and Habronema muscae) and one species of botflies from the genus Gasterophilus. Th e widest species diversity (18 species from 8 genera) was observed in strongylids: 2 species from the subfamily Strongylinae and 16 species from Cyathostominae. Distribution of strongylid species between ten prevalence classes revealed a bimodal structure (“core-satellite” mode) of the strongylid community. Th e results obtained in this study are to be considered as the initial data for the further parasitological monitoring of Przewalski’s horses at the Orenburg State Reserve.