Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible (IPADS, INTA Balcarce-CONICET), RN 226 Km 73.5, 7620 Balcarce, Buenos Aires, Argentina.
Instituto de Innovación para la Producción Agropecuaria y el Desarrollo Sostenible (IPADS, INTA Balcarce-CONICET), RN 226 Km 73.5, 7620 Balcarce, Buenos Aires, Argentina.
Vet Parasitol Reg Stud Reports. 2024 Oct;55:101107. doi: 10.1016/j.vprsr.2024.101107. Epub 2024 Aug 27.
Bovine lungworms (Dictyocaulus viviparus) are nematodes which cause a respiratory disease known as verminous bronchitis or pneumonia. In this paper, we describe 20 outbreaks of bovine dictyocaulosis recorded between 2000 and 2023 in Central Argentina. Outbreaks occurred more frequently during the autumn-winter season (from April to August) and affected cattle under 1 year old in beef production systems. An average morbidity and mortality of 26.22 % and 8.44 % were registered, respectively. The main clinical signs observed were respiratory distress (coughing, tachypnea, dyspnea, and nasal discharge), weight loss, weakness, decubitus, and diarrhea. Necropsies were performed in thirty-one calves, heifers, and steers. Gross findings included diffuse interstitial or multifocal pneumonia, with marbled appearance intermingling atelectasis and red-gray firm areas of consolidation, and subpleural and interlobular emphysema and edema. Microscopically, lungs were characterized by abundant edema and mixed intra-alveolar multifocal to coalescent infiltrate. Frequently, adult worms and/or larvae were spotted in the bronchi or alveoli, respectively. Some cases exhibited proliferation of type 2 pneumocytes and hyaline membranes covering the alveolar septa. Co-infections with gastrointestinal nematodes were frequently found in fecal samples. Given the perspective of anthelmintic resistance and future changes in environmental conditions due to climate change, integrated parasitic control strategies are mandatory and should be tailored to each production system. The information gathered in this research provides an overview of lungworm infections in livestock production systems from Central Argentina and could be useful for surveilling, monitoring and designing strategic interventions for the control of this important parasitic disease in the region.
牛肺线虫（Dictyocaulus viviparus）是一种引起呼吸道疾病的线虫，通常被称为肺丝虫性支气管炎或肺炎。本文描述了 2000 年至 2023 年期间在阿根廷中部记录的 20 起牛肺丝虫病暴发。暴发更频繁地发生在秋季至冬季（4 月至 8 月），并影响牛肉生产系统中 1 岁以下的牛。分别记录到 26.22%和 8.44%的平均发病率和死亡率。主要观察到的临床症状是呼吸窘迫（咳嗽、呼吸急促、呼吸困难和鼻腔分泌物）、体重减轻、虚弱、卧地不起和腹泻。在 31 头小牛、小母牛和公牛中进行了剖检。肉眼可见弥漫性间质性或多灶性肺炎，大理石样外观夹杂着肺不张和红色-灰色实变区，以及肋胸膜下和小叶间气肿和水肿。显微镜下，肺部特征为大量水肿和肺泡内混合性多灶性至融合性浸润。支气管或肺泡中常可见成虫和/或幼虫。一些病例表现为 2 型肺泡细胞增生和覆盖肺泡隔的透明膜。在粪便样本中经常发现与胃肠道线虫的混合感染。鉴于驱虫剂耐药性的前景以及气候变化导致未来环境条件的变化，综合寄生虫控制策略是强制性的，应根据每个生产系统进行调整。本研究收集的信息提供了阿根廷中部家畜生产系统中肺丝虫感染的概述，可用于监测、监控和设计该地区重要寄生虫病的控制战略。
