USE OF LARVAL CULTURES TO INVESTIGATE THE STRUCTURE OF STRONGYLE POPULATIONS IN WORKING HORSES, ROMANIA: PRELIMINARY DATA

Abstract

Strongyle parasites infecting grazing horses have different pathogenity potentials. For this reason, strongyle eggs with horse feces need to be differentiated into small and large strongyle species, usually by means of larval cultivation and subsequent microscopicidentification of third- stage larvae. The present study aims to provide an analysis of the strongyle populations composition based on different morphotypes of third stage strongyle larvae in naturally infected horses. In this regard, a coprological study was carried out to investigate the diversity of strongyle species in naturally infected working horses, in Northeastern Romania. For this, individual faecal samples were collected and examined qualitatively for parasitic infection, using a sodium chloride flotation method, and quantitatively for faecal strongyle egg count (eggs per gram - EPG), by a modified McMaster technique. Further larval cultures were performed from pooled positive samples for the identification of third-stage larvae (L3) of strongyle nematodes. All samples were positive for strongyle eggs,with an intensity rate varying from 50 to 2450 EPG. Larval identification showed mixed strongyle populations, with the following structure: small strongyles (92.9%), represented by the cyathostomin larvae type A (62%), type C (18.6%), type F (8.5%, and Gyalocephalus capitatus (3.8%), and large strongyles (4.5%) species, such as Oesophagodontus robustus (2.6%) and Craterostomum acuticaudatum (1.9%). Out of the total number of counted larvae, 2.6% could not be identified. The present study emphasizes that use of larval cultures allows a proper assessment of mixed strongyle populations in horses and it might represent an useful tool for further investigations into the epidemiology of equine strongyle infections in Romania.