背景:在三个牧场中,一个户外猪群受到严重呼吸道疾病的影响。尸检时,在肺部检测到猪肺炎支原体和多杀性巴氏杆菌,以及肺部蠕虫。Metacrongylusspp的生命周期。包括蚯蚓作为中间宿主,由于家猪主要在室内饲养,几十年来,在瑞典的家猪中没有诊断出肺虫感染,即使是在户外饲养的猪也没有。因此,从验证Metastrongylusspp的影响的角度对这种疾病的爆发进行了审查。
结果:在疾病爆发时,既不是Metacrongylusspp的卵。,在十周大的猪的粪便中检测到猪毛虫和A虫。相比之下,在牧场上患有呼吸道疾病的五个月大的猪每克(Epg)的scarissuum和高达1100Epg的Trichurissuis,而在另一个牧场的六个月大的健康猪中没有发现这些寄生虫的卵。来自Metacrongylusspp的卵数量少。在来自这两个年龄类别的粪便样本中观察到(<150Epg)。在屠杀时,七周后,将前一健康批次的十头正常体重猪与受影响批次的十头正常体重猪和五头小型猪进行比较。所有组均见支原体样肺炎病变愈合。所有的小猪都会在粪便中产卵,与大约50%的大型猪相比。Metastrongylusspp。在25头猪中的13头(52%)中被证明,代表包括所有组。
结论:作为中圆虫属。无论健康状况如何,在另一个健康的户外牧群中,Metacrongylusspp的影响。对呼吸道疾病的爆发进行了贬值。相反,在受影响的牛群中,有可能与A虫的高负担相关,这可能是在严重的呼吸道疾病暴发之前发生的。Further,结论是Metastrongylusspp。将在屠宰场进行的常规肉类检查中逃脱检测,并且它们似乎通常不会引起呼吸道疾病的临床症状。在户外生产中可能比以前认为的更常见。
BACKGROUND: An outdoor pig herd was affected by severe respiratory disease in one out of three pastures. At necropsy, Mycoplasma hyopneumoniae and Pasteurella multocida were detected in the lungs, as well as the lung worm Metastrongylus apri. The life cycle of Metastrongylus spp. includes earthworms as intermediate hosts, and since domestic pigs mainly are reared indoors, lungworm infections have not been diagnosed in domestic pigs in Sweden for decades, not even in pigs reared outdoors. Therefore, this disease outbreak was scrutinised from the view of validating the impact of Metastrongylus spp.
RESULTS: At the time of the disease outbreak, neither eggs of Metastrongylus spp., Trichuris suis nor Ascaris suum were detected in faeces of pigs aged ten weeks. In contrast, five-months-old pigs at the pasture with respiratory disease shed up to 3800 eggs per gram (Epg) of Ascaris suum and up to 1100 Epg of Trichuris suis, whereas eggs of these parasites were not demonstrated in healthy pigs aged six months at another pasture. Low numbers of eggs from Metastrongylus spp. (< 150 Epg) were seen in faecal samples from both these age categories. At slaughter, seven weeks later, ten normal weighted pigs in the preceding healthy batch were compared with ten normal weighted and five small pigs from the affected batch. Healing Mycoplasma-like pneumonic lesions were seen in all groups. All small pigs shed eggs of Ascaris suum in the faeces, compared to around 50% of the larger pigs. Metastrongylus spp. were demonstrated in 13 of the 25 pigs (52%), representing all groups included.
CONCLUSIONS: As Metastrongylus spp. were demonstrated regardless of health status, and also in another healthy outdoor herd, the impact of Metastrongylus spp. on the outbreak of respiratory disease was depreciated. Instead, a possible association with a high burden of Ascaris suum was suggested to have preceded the severe outbreak with respiratory disease in the affected herd. Further, it was concluded that Metastrongylus spp. will escape detection at routine meat inspections made at slaughterhouses, and as they appeared to generally not induce clinical signs of respiratory disease Metastrongylus spp. may be more common in outdoor production than previously believed.