INTRODUCTION. In Italy, Cyathostominae (small strongyles), are the most common parasites in donkey farms with prevalence rate of 100% (Buono, 2018, PhD Thesis). Although in donkey massive parasitic infections are often subclinical, the impact on their health is unclear and anthelmintic treatments are the main strategy to control these internal parasites (Matthews and Burden, 2013, Equine Vet. Educ, 25(9):461-67). The aims of the present study were to evaluate the efficacy of the main broad-spectrum horse anthelmintic drugs using Faecal Egg Count Reduction Test (FECRT), and to investigate a possible development of drug resistance, determining the Egg Reappearance Period (ERP), in donkeys naturally infected by Cyathostominae. MATERIALS AND METHODS. The trials were conducted in 2 donkey farms (A and B) located in Campania (Southern Italy) and Lazio region (Central Italy) respectively. Twenty-four animals for each farm were selected based on donkey selective therapy cut-off (FEC>300 egg per gram - EPG) and allocated to 4 treatment groups of 6 animals: Pyrantel (PYR), Fenbendazole (FBZ), Ivermectin (IVM) and Moxidectin (MOX). Donkeys were treated at horse dose rate for each tested drug. Faecal Egg Counts were performed at days -2, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77 and 84 post-treatment using the McMaster technique (detection limit of 10 EPG). At day 14, the mean efficacy of the different drugs was calculated, as Faecal Egg Count Reduction according to the formula: =[(−)/]100 (Nielsen et al., 2013, www.aaep.org). On each sampling day, group pooled faecal samples were incubated at 27°C for 7-10 days and third stage larvae (L3) were identified using the keys proposed by the Atlas of Diagnosis of Equine Strongylidosis (Cernea et al., 2008, Editura Academic Pres). RESULTS AND CONCLUSIONS. At 14 days post-treatment, in farm A FECRT was 100% for IVM and MOX, 99.8% for FBZ and 99.3% for PYR, suggesting that all investigated drugs were effective against Cyathostominae. For all tested drugs the ERPs were in accordance with those reported by the AAEP Guidelines. At 14 days, in farm B FECRT showed high efficacy for IVM and MOX (100%), a suspected resistance for PYR (86.3%) and resistance for FBZ (83.9%). ERPs were 8 weeks for IVM and 9 weeks for MOX, suggesting a shortened ERP rate for MOX. In all donkeys of both farms, coprocultures revealed the presence of Cyathostominae larvae. Based on our results the macrocyclic lactones were totally effective against small strongyles in donkeys, but to evaluate the anthelmintic resistance, it is crucial to associate the FECRT with the ERP value, because a shorter ERP is a precursor to the development of resistance.
Efficacy of major anthelmintics against cyathostominae in donkeys / Buono, F.; Roncoroni, C.; Pacifico, L.; Piantedosi, D.; Neola, B.; Fagiolo, A.; Veneziano, V.. - (2018), pp. 183-183. (Intervento presentato al convegno Atti del XXX Congresso della Società Italiana di Parassitologia (SoIPa) tenutosi a Milano nel 26-29 giugno 2018).
Efficacy of major anthelmintics against cyathostominae in donkeys
Buono F.;Pacifico L.
;Piantedosi D.;Neola B.;Veneziano V.
2018
Abstract
INTRODUCTION. In Italy, Cyathostominae (small strongyles), are the most common parasites in donkey farms with prevalence rate of 100% (Buono, 2018, PhD Thesis). Although in donkey massive parasitic infections are often subclinical, the impact on their health is unclear and anthelmintic treatments are the main strategy to control these internal parasites (Matthews and Burden, 2013, Equine Vet. Educ, 25(9):461-67). The aims of the present study were to evaluate the efficacy of the main broad-spectrum horse anthelmintic drugs using Faecal Egg Count Reduction Test (FECRT), and to investigate a possible development of drug resistance, determining the Egg Reappearance Period (ERP), in donkeys naturally infected by Cyathostominae. MATERIALS AND METHODS. The trials were conducted in 2 donkey farms (A and B) located in Campania (Southern Italy) and Lazio region (Central Italy) respectively. Twenty-four animals for each farm were selected based on donkey selective therapy cut-off (FEC>300 egg per gram - EPG) and allocated to 4 treatment groups of 6 animals: Pyrantel (PYR), Fenbendazole (FBZ), Ivermectin (IVM) and Moxidectin (MOX). Donkeys were treated at horse dose rate for each tested drug. Faecal Egg Counts were performed at days -2, 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77 and 84 post-treatment using the McMaster technique (detection limit of 10 EPG). At day 14, the mean efficacy of the different drugs was calculated, as Faecal Egg Count Reduction according to the formula: =[(−)/]100 (Nielsen et al., 2013, www.aaep.org). On each sampling day, group pooled faecal samples were incubated at 27°C for 7-10 days and third stage larvae (L3) were identified using the keys proposed by the Atlas of Diagnosis of Equine Strongylidosis (Cernea et al., 2008, Editura Academic Pres). RESULTS AND CONCLUSIONS. At 14 days post-treatment, in farm A FECRT was 100% for IVM and MOX, 99.8% for FBZ and 99.3% for PYR, suggesting that all investigated drugs were effective against Cyathostominae. For all tested drugs the ERPs were in accordance with those reported by the AAEP Guidelines. At 14 days, in farm B FECRT showed high efficacy for IVM and MOX (100%), a suspected resistance for PYR (86.3%) and resistance for FBZ (83.9%). ERPs were 8 weeks for IVM and 9 weeks for MOX, suggesting a shortened ERP rate for MOX. In all donkeys of both farms, coprocultures revealed the presence of Cyathostominae larvae. Based on our results the macrocyclic lactones were totally effective against small strongyles in donkeys, but to evaluate the anthelmintic resistance, it is crucial to associate the FECRT with the ERP value, because a shorter ERP is a precursor to the development of resistance.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
