Onderka D K
Alberta Department of Agriculture, Animal Health Division, Edmonton, Canada.
J Wildl Dis. 1989 Apr;25(2):218-24. doi: 10.7589/0090-3558-25.2.218.
Two genera of lung nematodes were found in a sample of 382 wild ringed seals (Phoca hispida). Otostrongylus circumlitus were found mainly in young of the year where they occupied the main stem bronchi causing extensive mucus production, mucosal hyperplasia and peribronchitis. Immature stages of the nematode were found in pulmonary vessels causing end-arteritis. There was only a slight reduction in respiratory parenchyma in infected seals and no correlation between infection and size or body condition. However, the sharp decline of O. circumlitus infection from 32% in young of the year to 0.5% after the first winter suggests that this parasite may play a role in the population dynamics of ringed seals. Filaroides (Parafilaroides) hispidus was found in alveoli of seals throughout all age classes causing no significant lesions. The infection rate increased from 44 to 71% in the 7 to 13-yr-old animals and declined to 38% in older seals. Concurrent infections occurred in 28% of young of the year seals.
在382只野生环斑海豹（Phoca hispida）的样本中发现了两种肺线虫。环纹耳状线虫主要在当年幼崽中被发现，它们占据主支气管，导致大量黏液产生、黏膜增生和支气管周炎。线虫的未成熟阶段在肺血管中被发现，导致终末动脉炎。受感染海豹的呼吸实质仅有轻微减少，感染与体型或身体状况之间无相关性。然而，环纹耳状线虫感染率从当年幼崽的32%在第一个冬季后急剧下降至0.5%，这表明这种寄生虫可能在环斑海豹的种群动态中起作用。海豹丝状线虫（副丝状线虫属）在所有年龄组的海豹肺泡中均有发现，未造成明显病变。在7至13岁的动物中，感染率从44%增至71%，而在年龄较大的海豹中降至38%。28%的当年幼崽海豹发生了混合感染。
