DYNAMICS OF INTESTINAL PARASITE INFECTION IN PRZEWALSKI’S HORSES REINTRODUCED TO PRE-URALS STEPPE, ORENBURG STATE NATURE RESERVE (RUSSIA)

Autor: Stanislav Platonov, Evgeniy A. Bulgakov, Vladislav Belimenko, Pavel Khristianovsky, Vladimir Yu. Petrov, Dina E. Khuzhakhmetova, «Shaitan-Tau», Tatjana L. Zharkikh, Rafilia T. Bakirova
Rok vydání: 2019
Předmět:
Zdroj: Nature Conservation Research: Zapovednaâ Nauka, Vol 4, Iss Suppl.2, Pp 23-30 (2019)
ISSN: 2500-008X
DOI: 10.24189/ncr.2019.027
Popis: The first successful reintroduction programme for the Przewalski's horse in Russia was launched by FSFI «Orenburg Reserves» in 2015. A total of 36 Przewalski's horses were brought to the Pre-Urals Steppe site from semi-reserves in France and Hungary in 2015–2017. Parasite infections can significantly affect the survival of the wild horses during the process of adaptation. Investigation of the level of helminth infections in these reintroduced horses is the subject of their regular monitoring in the Pre-Urals Steppe. The studies were conducted on the territory of the Pre-Urals Steppe of 165.38 km2, in Orenburg State Nature Reserve in 2016–2019. The coprological examinations were conducted on a monthly basis using the McMaster method. The Baerman-Orlov larvoscopy technique was used to identify the larval stages of nematodes. Przewalski's horses were threatened with anthelmintic drugs every 3 to 12 months. All faecal samples collected in two or more months after deworming, contained eggs of nematodes of the family Strongylidae (Nematoda, Strongylida), the prevalence of infection was 100%. Single eggs of cestodes from the genus Anoplocephala (Cestoidea: Anoplocephalidae) were found in four samples out of 642. Larvoscopy revealed larvae of the nematodes from the genus Triodontophorus (subfamily Strongylinae) and larvae from the subfamily Cyathostominae. In addition, a small number of larvae of the II and III stages of the gastric botfly Gastrophilus spp. (family Gastrophilidae), were found in the faeces in some Przewalski's horses after deworming. Parascaris equorum was not registered in this study, although this parasite was found in domestic horses from the village nearest to the Pre-Urals Steppe. During the study period, there were no noticeable seasonal fluctuations in the number of helminth eggs; the level of EPG (eggs per gram of faeces) value gradually increased in all groups of horses after deworming. A high level of infection (> 500 EPG) was reached in 1–6 months after deworming; the maximal level was registered in September 2018 (2483.3 ± 718.5 EPG in one of the single-sex groups). The comparatively high EPG values did not affect the physical condition of Przewalski's horses in the Pre-Urals Steppe; no clinical signs of parasite infections were observed in our study. The level of strongylid infection in free-roaming breeding groups of Przewalski's horses was lower than that of animals kept in acclimatization enclosures. There was a noticeable trend towards a decrease in the average EPG level of the breeding groups. This may be due to two factors: 1) contamination of grass in the enclosures was higher because of higher density of horses; 2) the breeding groups transported in 2015 and 2016, had more time for the adaptation. Regular deworming is not recommended for relocated wild horses outside an adaptation period as it may influence their natural resistance to parasitic infections and poses a risk of the emergence of resistant helminth populations. Preventive deworming of the Przewalski's horses should be administered only within the first years after their relocation to new areas.
Databáze: OpenAIRE
Externí odkaz: