November 2018

Signalment (JPC #1782714):  3-month old Hereford calf

HISTORY:  This calf had a history of severe chronic diarrhea and oral erosions for a 1-week period prior to death. 

MICROSCOPIC DESCRIPTION:  Slide D-V21a:  Rumen:  Focally extensively, rumenal mucosal epithelium is thickened up to 2mm (hyperplastic) with acanthosis and markedly swollen squamous epithelial cells with abundant clear to light eosinophilic, flocculent, vacuolated cytoplasm (ballooning degeneration), and often contain a single, up to 20 um, eosinophilic, intracytoplasmic viral inclusion body.  Multifocally, vacuolated cells coalesce to form clear spaces up to 100-200 um in diameter which often contain numerous viable and degenerate neutrophils admixed with fibrin, hemorrhage and necrotic debris (intraepithelial pustules) and scattered single cell necrosis.  Multifocally epithelium is eroded, ulcerated and replaced by cellular and karyorrhectic debris, abundant viable and degenerate neutrophils, and scattered colonies of superficial cocci (serocellular crust), and the remaining hyperplastic epithelium contains moderate parakeratotic hyperkeratosis.  The lamina propria and submucosa contains abundant degenerate neutrophils, fewer macrophages, lymphocytes and plasma cells, and hemorrhage, and blood vessels often contain plump endothelial cells (reactive).  Collagen bundles within the lamina propria and submucosa and muscle bundles of the tunica muscularis are separated by increased clear space, with multifocal ectatic lymphatics (edema).

Tongue:  Multifocally, myocytes within the tunica muscularis are mildly hypereosinophilic, with loss of cross-striations and pyknotic nuclei (degeneration and necrosis), with small cytoplasmic aggregates of a basophilic globular to granular material (mineralization).

Slide D-V21b:  Esophagus:  Affecting over 70% of the section, the mucosal epithelium is thickened up to 1 mm (hyperplastic), and there is extensive, severe intracellular edema (ballooning degeneration), with similar formation of intraepithelial pustules, and numerous previously described eosinophilic intracytoplasmic viral inclusion bodies. Focally, there is an extensive area of ulceration and replacement with moderate amounts of eosinophilic cellular and karyorrhectic debris, viable and degenerate neutrophils, hemorrhage, abundant fibrin, granulation tissue and many superficial cocci (serocellular crust).  In the adjacent subepithelial connective tissue, there is diffuse mild congestion and many viable and degenerate neutrophils, fewer macrophages, lymphocytes, and plasma cells.  Blood vessels often contain plump endothelial cells (reactive). 


  1. Rumen:  Rumenitis, proliferative and necrotizing, subacute, focally extensive, severe, with ballooning degeneration, hyperkeratosis, intraepithelial pustules and numerous epithelial eosinophilic intracytoplasmic viral inclusion bodies, Hereford, bovine.
  2. Esophagus: Esophagitis, proliferative and necrotizing, subacute, diffuse, severe, with ballooning degeneration, intraepithelial pustules and numerous epithelial eosinophilic intracytoplasmic viral inclusion bodies.
  3. Tongue, myocytes: Necrosis and mineralization, multifocal, minimal. 

ETIOLOGIC DIAGNOSIS:  Parapoxviral esophagitis and rumenitis

CAUSE:  Bovine papular stomatitis virus (bovine parapoxvirus)

CONDITION:  Bovine papular stomatitis; infectious ulcerative stomatitis and esophagitis









Oral lesions in cattle


Other Parapoxviruses


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