Endosymbiotic Intestinal Ciliates (Ciliophora) of Domestic Horses (Equus caballus Linnaeus, 1758) in Libya

In this study, the composition and distribution of intestinal ciliates, which are endosymbionts, were investigated in fecal samples from 30 domestic horses in Susah, Libya. One morphotype and 16 ciliate species belonging to 13 genera and 5 families were identified. Five of the horses did not harbor any ciliates. The genus Cycloposthium was present in 23 of the remaining horses, represented by the species C. bipalmatum, with a prevalence of 76.7%. In contrast, Holophryoides macrotricha, Tetratoxum parvum, and Triadinium caudatum were each observed in only one horse, with a prevalence of 3.3%. The number of species identified per horse ranged from 0 to 9, with an average of 4.3 ± 2.1. The average density of intestinal ciliates in the horses was 7.0 ± 6.2 × 10⁴ cells mL⁻¹. This is the first report on intestinal ciliates in horses in Libya.