Sable Island, Nova Scotia, Canada hosts one of few natural populations of feral horses (Equus caballus) never exposed to anthelmintics. Coproculture revealed cyathostomes, Strongylus equinus, S. edentatus, and S. vulgaris, with S. equinus (unusually) dominating in adult horses and cyathostomes dominating in young horses (<3 years of age). We examined 35 horses found dead in the springs of 2017 and 2018, as well as fecal samples from live horses in spring (n = 45) and summer 2018 (n = 236) using McMaster fecal flotation and Baermann larval sedimentation on fresh samples, and modified Wisconsin flotation and sucrose gradient immunofluorescent assay for Giardia and Cryptosporidium on frozen samples. Mean strongyle fecal egg counts were 666 eggs per gram (EPG) in dead horses, 689 EPG in live horses in spring, and 1105 EPG in summer; domestic horses are usually treated at counts exceeding 200 EPG. Adult horses (unusually) had patent infections with the lungworm Dictyocaulus arnfieldi and ascarids (Parascaris spp.), and in spring, dead horses had 5 times higher odds of having patent ascarid infections than live horses, likely due to malnutrition and corresponding immunodeficiency. Fecal prevalence and intensity of D. arnfieldi and Parascaris spp. were significantly higher in young horses, and in spring versus summer. A higher proportion of fecal samples were positive for strongyle and ascarid eggs using a centrifugal flotation technique on previously frozen feces, as compared to a passive flotation method on fresh feces. Eggs of the tapeworm Paranoplocephala mamillana were present in fecal samples from 28% of live, and 42% of dead, horses in spring. This research represents several new geographic records (S. edentatus, D. arnfieldi, and Eimeria leuckarti), provides insight into unusual patterns of parasite epidemiology in a nutrition-limited environment, and has conservation and biosecurity implications for this unique equine population, as well as for parasite management in domestic horses.

中文翻译：

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不遵守规则：加拿大黑貂岛上的野生马自然种群中的寄生虫流行病学异常模式。

加拿大新斯科舍省的黑貂岛是野生马（Equus caballus）的少数自然种群之一，从未接触过驱虫药。共培养表明，在成年马中，小马链球菌占主导地位，而在幼马中（<3岁），在小马蝇中占主导地位（通常）的是马鞭草（Sydhostusomes），马蝇（Strongylus equinus），马氏链球菌（S. edentatus）和寻常链球菌（S. vulgaris）。我们使用McMaster粪便浮选和Baermann幼虫沉淀法，对2017年春季和2018年春季发现的35匹死马以及春季（n = 45）和2018年夏季（n = 236）活马的粪便样本进行了研究，改良的威斯康星浮选法和蔗糖梯度免疫荧光法测定冷冻样品上的贾第虫和隐孢子虫。在死马中，粪便中的强壮粪便鸡蛋平均数量为666鸡蛋/克（EPG），在春季，在活马中为689 EPG，在夏天为1105 EPG；家养马匹的处理量通常超过200 EPG。成年马（通常）患有肺线虫（Dictyocaulus arnfieldi）和a虫（Parascaris spp。）的专利感染，而在春季，死马被patent虫的专利感染的几率是活马的5倍，这可能是由于营养不良和相应的免疫缺陷所致。D. arnfieldi和Parascaris spp的粪便患病率和强度。在幼马中，春季和夏季明显高于幼马。与新鲜粪便的被动浮选方法相比，使用离心浮选技术对先前冷冻的粪便中的粪便样本中的坚韧卵和scar虫卵阳性的比例更高。在春季，粪便样本中有28％的活马和42％的死亡马中有the虫Paranoplocephala mamillana的卵。