Eosinophilic encephalomyelitis in horses caused by protostrongylid parasites
Eun-Jung Bak1, Young-Hwa Jean2, Gye-Hyeong Woo3,*
1College of Dentistry, Yonsei University, Seoul 03722, Korea
2Animal, Plant and Fisheries Quarantine and Inspection Agency, Gimcheon 39660, Korea
3Laboratory of Histopathology, Department of Clinical Laboratory Science, Semyung University, Jecheon 27136, Korea
Correspondence to: Tel: +82-43-649-1539; Fax: +82-43-649-7361; E-mail: ghwoo@naver.com
Received: October 24, 2016; Revised: January 9, 2017; Accepted: February 7, 2017; Published online: April 6, 2017.
Four thoroughbred horses showing lameness, ataxia, circling, depression, recumbency, and seizures, were submitted. The horses had grossly weak to dark red appearances and foci in the central nervous system. Multifocal to coalescing eosinophilic necrotizing encephalomyelitis was observed histologically in the CNS as well as intact or degenerated nematodes. Nematodes had polymyarian-coelomyarian musculature, a smooth thin cuticle, and intestines lined by multinucleated cells with microvilli. These traits suggested the nematodes belonged to the family Protostrongylidae, which includes P. tenuis. It was concluded that the horses were infested with nematodes, presumably P. tenuis, which resulted in eosinophilic necrotizing encephalomyelitis.
Keywords: central nervous system, encephalomyelitis, horse, nematode, Parelaphostrongylus tenuis

© 2017 The Korean Society of Veterinary Science.