Background: 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.

背景：在过去的十年中，Parascaris spp。许多国家都记录了对驱虫药的抗药性。在沙特阿拉伯，关于Parascaris spp的数据有限。抗驱虫药。

目的：确定伊维菌素，阿维菌素和吡喹酮合用的现状以及芬苯达唑对寄生虫的抗药性。在沙特阿拉伯的马匹中。

方法：通过粪便卵数（FEC）检查来自11个不同农场的314只小马驹。驹是所有17.2±4.5（SD）个月大的阿拉伯马。在第0天施用伊维菌素（n = 46只驹），阿维菌素和吡喹酮合用（n = 46）和芬苯达唑（n = 46），并在第14天收集粪便。该研究包括41只未经处理的驹。FEC≥100蛋/克（EPG）的动物用于测量驱虫效果。寄生虫spp。当粪便卵数减少（FECR）≥95％与较低的95％置信限（LCL）> 90％相关时，这些人群被视为易感人群；当FECR≤90％或LCL <90％时，可疑人群具有耐药性；当FECR <90％时，则具有耐药性LCL <90％。

结果：寄生虫的患病率。感染率为53％（179/341匹马）。寄生虫对寄生虫的抗性。芬苯达唑（55％的农场和65％的小马驹）施用后最高，而伊维菌素或阿维菌素和吡喹酮的组合占27％的农场（和46％的小马驹）和18％的农场（和10）驹的百分比）。

结论：这些数据表明抗寄生虫药寄生的寄生虫。沙特阿拉伯的养马场里有很多种群。