sentence: To determine the current status of ivermectin , abamectin and praziquantel combined , and fenbendazole resistance to Parascaris spp . in horses in Saudi Arabia .
paragraph: A field study on the anthelmintic resistance of Parascaris spp. in Arab foals in the Riyadh region, Saudi Arabia. In the last decade, Parascaris spp. resistance to anthelmintics has been recorded in many countries. In Saudi Arabia, there are limited data available on Parascaris spp. resistance to anthelmintics. ### objective To determine the current status of ivermectin , abamectin and praziquantel combined , and fenbendazole resistance to Parascaris spp . in horses in Saudi Arabia . ### methods Three hundred and forty-one foals from eleven different farms were examined by faecal egg count (FEC). The foals were all Arab horses aged 17.2 ± 4.5 (SD) months. ivermectin (n = 46 foals), abamectin and praziquantel combined (n = 46), and fenbendazole (n = 46) were administered on day 0 and faeces were collected on day 14. The study comprised 41 untreated foals as controls. Animals that have FEC of ≥100 eggs per gram (EPG) were used to measure anthelmintic efficacy. Parascaris spp. populations were considered susceptible when faecal egg count reduction (FECR) was ≥95% associated with a lower 95% confidence limit (LCL) >90%, suspected resistant when FECR ≤90% or LCL <90% and resistant when FECR <90% and LCL <90%. ### results Prevalence of Parascaris spp. infection was 53% (179/341 horses). Anthelmintic resistance to Parascaris spp. were highest following fenbendazole (55% of farms and 65% of foals) and to a lower extent following ivermectin or the combination of abamectin and praziquantel which comprised 27% of farms (and 46% of foals) and 18% of farms (and 10% of foals), respectively. ### conclusion These data indicate that anthelmintics-resistant Parascaris spp. populations are present on horse farms in Saudi Arabia.