Department of Animal Medicine, Production and Health, University of Padova, Viale dell'Università, 16, Legnaro, PD, 35020, Italy.
Veterinary practicioner, Trento, Italy.
BMC Vet Res. 2024 Oct 30;20(1):498. doi: 10.1186/s12917-024-04347-7.
Anthelmintic resistance (AR) is a global threat to grazing livestock farming. In Italy, anthelmintic efficacy remains high compared to other European countries, but many parts of the country haven't been investigated yet. Local veterinary practitioners from Trentino and Veneto regions reported suspected inefficacy towards anthelmintic drugs in some of their farms, prompting a study on AR in sheep and goat farms of northern Italy. The study aimed to assess anthelmintic effectiveness using genus-specific faecal egg count reduction tests (FECRT), to detect differences in treatment response among nematode genera involved in the infection.
Twelve farms (6 sheep and 6 goat farms) were included based on clinical suspicion of AR. Treatments were carried out with either benzimidazoles (BZ) or macrocyclic lactones (ML) Treatment was effective in 3/6 goat trials, with reduced effectiveness to BZ in two farms and to ML the last one. In sheep farms (6/6), effectiveness was consistently and more severely insufficient. Ineffectiveness was particularly high towards Haemonchus contortus, while Oesophagostomum/Chabertia maintained susceptibility in nearly all trials. Trichostrongylus/Teladorsagia exhibited intermediate results.
This study reveals diminished efficacy of both BZ and ML in small ruminant farms in north-eastern Italy, an area previously lacking data on the topic, except for goats in South Tyrol. Variability in treatment responses among nematode genera support suspicions of AR, and further concerns are raised by the prevalence of treatment ineffectiveness against the highly pathogenic Haemonchus contortus. This finding underscores the urgent need for comprehensive AR monitoring in the area and improved management practices to prevent further resistance development and protect livestock health.
驱虫药耐药性（AR）是全球放牧家畜养殖面临的威胁。与其他欧洲国家相比，意大利的驱虫药疗效仍然很高，但该国仍有许多地区尚未进行调查。特伦蒂诺和威尼托地区的当地兽医报告称，他们在一些农场发现驱虫药疗效不佳，这促使人们对意大利北部的绵羊和山羊养殖场进行了驱虫药耐药性研究。该研究旨在使用属特异性粪便卵囊减少计数测试（FECRT）评估驱虫药的效果，以检测感染中涉及的线虫属之间的治疗反应差异。
根据对驱虫药耐药性的临床怀疑，有 12 个农场（6 个绵羊场和 6 个山羊场）入选。用苯并咪唑（BZ）或大环内酯（ML）进行治疗。在 3/6 的山羊试验中，治疗有效，其中 2 个农场对 BZ 的效果降低，最后 1 个对 ML 的效果降低。在绵羊场（6/6）中，效果始终且更严重不足。对捻转血矛线虫的无效性特别高，而奥斯特线虫/恰伯氏属在几乎所有试验中均保持敏感性。对粗纹食道口线虫/泰氏血矛线虫的效果则介于两者之间。
这项研究揭示了意大利东北部小反刍动物养殖场中 BZ 和 ML 的疗效下降，该地区此前在这方面缺乏数据，只有南蒂罗尔的山羊例外。线虫属之间的治疗反应差异支持对 AR 的怀疑，而对高度致病性捻转血矛线虫治疗无效的普遍性则引发了更多的担忧。这一发现强调了该地区全面监测 AR 和改进管理实践的迫切需要，以防止进一步的耐药性发展并保护牲畜健康。
