An outbreak of compressive myelopathy due to pyogranulomatous reaction to the oily adjuvant of the foot-and-mouth disease vaccine - case report

Fabrício Gomes Melo ,M.E Godoy,A.ú Carvalho ,Elias Jorge Facury Filho ,Rodrigo Melo Meneses ,Felipe Pierezan

doi:10.1590/1678-4162-10609

Abstract

ABSTRACT Cases of compressive myelopathy syndrome associated with post vaccinal pyogranulomas were diagnosed post mortem in three cows from a farm in Minas Gerais state, Brazil. These cows presented ataxia and bilateral paresis of the pelvic limbs, which evolved to paralysis, and sternal recumbence. On necropsy, locally extensive areas of the longissimus dorsi muscle were replaced by pyogranulomas supported by moderate amounts of fibrous connective tissue. On the cut surface, some nodules contained yellowish and viscous fluid (purulent exudate) or whitish fluid (interpreted as the oily adjuvant of a vaccine). In the spinal canal of the subjacent vertebrae, compressing the spinal cord, were pyogranulomas identical to those described in the skeletal muscle. Histologically, the pyogranulomas were composed of a central clear vacuole (consistent with the space left by the oil adjuvant droplets), surrounded by neutrophils and, more externally, by large numbers of epithelioid macrophages and fewer multinucleated giant cells. In the white matter of the spinal cord were numerous well-defined, clear vacuoles (Wallerian degeneration). The association of the clinical history and pathological findings allowed the diagnosis of compressive myelopathy associated with pyogranulomatous reaction to the oily adjuvant of the foot-and-mouth disease vaccine, in this case, due to its inadequate application.

Highlights

Compressive myelopathies are uncommon in ruminants and are associated with spaceoccupying lesions in the spinal canal, such as abscesses, granulomas, traumas, malformations and neoplasms (Sherman and Ames, 1986; McAllister et al, 1995, O’Toole et al, 1995; Borges et al, 2003; Ubiali et al, 2011; Panziera et al, 2014; Panziera et al, 2016)
Granulomas within the spinal canal have been described in association to post vaccinal reactions to the oily adjuvant of vaccines in the USA and Brazil (McAllister et al, 1995; O’Toole et al, 1995; O’Toole et al, 2005; Ubiali et al, 2011; Marques et al, 2012; Panziera et al, 2016)
2016), 35 cows died after presenting similar clinical signs characterized by ataxia, paresis and paralysis of the thoracic or pelvic limbs, emaciation, and sternal recumbency

Summary

INTRODUCTION

Compressive myelopathies are uncommon in ruminants and are associated with spaceoccupying lesions in the spinal canal, such as abscesses, granulomas, traumas, malformations and neoplasms (Sherman and Ames, 1986; McAllister et al, 1995, O’Toole et al, 1995; Borges et al, 2003; Ubiali et al, 2011; Panziera et al, 2014; Panziera et al, 2016). 2016), 35 cows died after presenting similar clinical signs characterized by ataxia, paresis and paralysis of the thoracic or pelvic limbs, emaciation, and sternal recumbency. The duration of these signs varied from 5 to 60 days. In the skeletal muscle and spinal canal, the muscle fibers, epidural space and dura mater were expanded, and partially to completely effaced by extensive areas of pyogranulomatous inflammation with proliferation of fibrous connective tissue. No lesion was observed in the brain, as well in the other submitted tissues

DISCUSSION

Findings

CONCLUSION