Conference 09 - 2025 Case: 04 20251022

Wednesday Slide Conference, 2025-2026, Conference 9, Case 4

Signalment:

Six day-old piglet, male, cross-breed (Sus scrofa domestica)

History:

Gross Pathology: Six-day-old piglet of 1.16 kg weight with poor body condition and prominent bone protuberances. In a multifocal to generalized pattern throughout the skin and tongue, there were circular 0.1 to 0.5 cm in diameter lesions characterized by slightly prominent, firm, and well circumscribed aspect (papules and pustules); most of them were brownish in color with central umbilication and crusted. Significant lesions were not found in internal organs or in the subcutaneous tissue.

Laboratory Results:

N/A

Microscopic Description:

Haired skin (ear, prepuce, and inguinal area): affecting 20% of the evaluated section there is a proliferative and necrotizing process that mainly affects the epidermis. The epidermis and hair follicle epithelium show the following features: stratum corneum with diffuse mild compact hyperkeratotic orthokeratosis with multifocally serocellular crusts composed by cellular debris, degenerated keratin, degenerated neutrophils, and multiple superficial coccoid bacterial colonies (secondary contamination). Also, stratum spinosum shows multifocal marked thickening (acanthosis), and numerous keratinocytes display ballooning degeneration and intracytoplasmic perinuclear 2-5 µm eosinophilic inclusion bodies. Multifocally, in the most affected areas, there is marked neutrophilic exocytosis, and numerous keratinocytes lost intercellular connections and undergo lytic necrosis. Superficial and mid dermis show perivascular to diffuse, moderate to severe inflammatory infiltrates composed by viable and degenerated neutrophils, macrophages, and lesser numbers of lymphocytes and plasma cells. Significant lesions were not seen in the hypodermis.

Contributor's Morphologic Diagnoses:

Morphologic diagnosis: Haired skin; severe, subacute, proliferative, necrotizing, and crusting dermatitis with intracytoplasmic eosinophilic inclusion bodies. Etiologic diagnosis: Poxviral dermatitis. Etiology: Swine poxvirus.

Contributor's Comment:

TBD

Contributing Institution:

Veterinary Pathology Department Veterinary Faculty, Autonomous University of Barcelona, 08193 Bellaterra, Barcelona, Spain. https://www.uab.cat/web/els-serveis/-servei-diagnostic-de-patologia[1]veterinaria1297063220061.html