Contents lists available at ScienceDirect Veterinary Parasitology journal homepage: www.elsevier.com/locate/vetpar Research paper Anthelmintic activity of injectable eprinomectin (eprecis ® 20 mg/mL) in naturally infected dairy sheep Sofia-Afroditi Termatzidou a , Konstantinos Arsenopoulos b , Nektarios Siachos a , Panagiota Kazana a , Elias Papadopoulos b , Damien Achard c , Hamadi Karembe c , Georgios Bramis d , Georgios Arsenos a, ⁎ a Laboratory of Animal Husbandry, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, 54124, Greece b Laboratory of Parasitology and Parasitic Diseases, Faculty of Veterinary Medicine, School of Health Sciences, Aristotle University of Thessaloniki, 54124, Greece c Ceva Santé Animale, Libourne, France d Ceva Hellas Ltd, Agiou Nikolaou 15, Alimos, 17455, Greece ARTICLE INFO Keywords: Dairy sheep Gastrointestinal nematodes Efficacy Eprinomectin Injectable Formulation ABSTRACT The anthelmintic activity of an injectable eprinomectin formulation (Eprecis ® 20 mg/mL) was evaluated in 150 naturally infected dairy sheep raised in 3 semi-intensive flocks. All ewes were at the same stage of lactation and grazed on natural pastures. Ewes did not receive any anthelmintic treatment for at least 4 months prior to the experiment. In each flock, 50 ewes were selected and randomly allocated to control (C) or treatment (T) groups (n = 25 per group). Groups were balanced according to the ewes’ bodyweight (BW) and fecal egg count (FEC) measured seven days before eprinomectin administration (day-7). On study day 0, ewes in group T, received 0.2 mg/kg BW of eprinomectin subcutaneously (Eprecis ® 20 mg/mL, Ceva). Ewes in group C were left untreated. Fecal samples were collected on day 0, 7, 14, 21 and 28 post-treatment to assess FEC and for coprocultures. Ewes were weighed on day 0 and 28. Overall and within-flock efficacy of eprinomectin was calculated throughout the experimental period. No local or general adverse reaction after injection was observed. The most prevalent parasite genera were Teladorsagia, Haemonchus and Trichostrongylus. Following treatment, the overall mean FEC of C and T groups differed significantly (P < 0.001). Overall and within-flock efficacy of eprinomectin was 99.8%–100.0% and 99.7%–100.0%, respectively. Contrary to C group, ewes treated with injectable eprino- mectin increased their BW during the study (-0.5 kg vs. + 1.5 kg, P < 0.001). In this field study, a single subcutaneous injection of eprinomectin to dairy sheep, at 0.2 mg/kg BW, resulted in excellent curative an- thelmintic activity; egg counts remain low for at least 28 days after treatment. 1. Introduction In Greece, small ruminants are mainly raised for milk production. Around 80% of sheep flocks are reared under semi-intensive conditions; grazing on natural pastures year-round and supplemented with con- centrates and alfalfa hay during winter. Under these conditions, sheep and especially lactating ewes are challenged with gastrointestinal ne- matodes which cause a reduction in voluntary feed intake, health problems and significant economic losses due to impaired milk pro- duction (Papadopoulos et al., 2003; Laurenson et al., 2011). Control of endoparasites in lactating ewes is challenging. Considering that pasture management strategies are uncommon in Greek flocks, control of endoparasites depends heavily on anthelmin- tics. However, very few anthelmintics are licensed for lactating ewes. Albendazole is an option but, requires withdrawal of milk for at least four days. Hence, it is not used in lactating ewes but rather in dry ewes or after lambing. But. there is evidence in the literature suggests about significant anthelmintic resistance to benzimidazoles (Kaplan and Vidyashankar, 2012; Gallidis et al., 2012). Eprinomectin is proposed as a good option for the control of gastrointestinal nematodes in lactating ewes because it combines a zero day milk withdrawal period with a broad spectrum anthelmintic activity against gastrointestinal nema- todes, lungworms and some ectoparasites (Cringoli et al., 2003). Epri- nomectin is available as injectable solution for cattle at a dose rate of 0.2 mg/kg (Eprecis ® 20 mg/mL, Ceva) and as pour on formulation for cattle and small ruminants at 0.5 or 1.0 mg/kg (Eprinex ® Multi, Boeh- ringer Ingelheim), respectively. Parenteral administration of eprino- mectin appears to be preferable given the higher bioavailability (Briqué-Pellet et al., 2017) and the lower variability in drug exposure (EMA, 2017). Moreover, the topical use of eprinomectin in sheep is not https://doi.org/10.1016/j.vetpar.2018.12.014 Received 26 August 2018; Received in revised form 28 November 2018; Accepted 21 December 2018 ⁎ Corresponding author at: P.O. Box: 393, 541 24 Thessaloniki, Greece. E-mail address: arsenosg@vet.auth.gr (G. Arsenos). Veterinary Parasitology 266 (2019) 7–11 0304-4017/ © 2019 Elsevier B.V. All rights reserved. T