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. 2021 Sep;33(5):949-951.
doi: 10.1177/10406387211021489. Epub 2021 Jun 2.

Parasitic encephalitis caused by Stephanurus dentatus in a pig in Brazil

Robert G S Prado  1 , Chris H Gardiner  2 , Márcio A O Moura  1 , Gerson B E Gonzalez  1 , Marcos D Duarte  1 , Tiago F S Santos  1 , Pedro S Bezerra  1 , Valíria D Cerqueira  1 , Alessandra S Amaral  1 , Gabriela Riet-Correa  1
Affiliations

Parasitic encephalitis caused by Stephanurus dentatus in a pig in Brazil

Robert G S Prado et al. J Vet Diagn Invest. 2021 Sep.

Abstract

A pig was in left lateral recumbency with limb spasticity, accentuated prostration, and strabismus, and was euthanized. During autopsy, yellowing of the leptomeninges at the ventral pons to medulla oblongata was noted. In the cerebellar peduncles, there was a focally extensive black-to-yellow area at the level of the vestibular nuclei. Histologic examination revealed a cross-section of a nematode larva, consistent with Stephanurus dentatus, bordered by edema and marked infiltration of mononuclear cells, plasma cells, and a few eosinophils. Vacuolation of the neuropil, with rare gitter cells and axonal spheroids, was also observed. We diagnosed parasitic encephalitis caused by S. dentatus migration based on the pathology findings and characterization of the parasite.

Keywords: Brazil; Stephanurus dentatus; central nervous system; swine.

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Conflict of interest statement

Declaration of conflicting interests: The authors declared no potential conflicts of interest concerning the research, authorship, and/or publication of this article.

Figures

Figures 1–4.
Figures 1–4.
Parasitic encephalitis caused by Stephanurus dentatus in a pig. Figure 1. The sow was in left lateral recumbency with spasticity of all 4 limbs. Figure 2. An extensive black-yellow area is present in the left cerebellar peduncle region. Figure 3. A nematode in cross-section is encircled by edema and a marked inflammatory infiltrate within an area of neuropil rarefaction. H&E. Bar = 100 μm. Figure 4. The nematode S. dentatus is characterized by a thin cuticle and platymyarian-meromyarian musculature (m); well-developed intestine (i) lined by multinucleate cells with a prominent brush border; vacuolated lateral chords (L) often divided into 3 sublaterals; and genital tracts (g). H&E. Bar = 50 μm.
See this image and copyright information in PMC

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