Wednesday Slide Conference, 2025-2026, Conference 9, Case 3
Signalment:
1 year and 11 months old, Mare, Standardbred Horse (Equus cabal/us)History:
Gross Pathology: The horse was in slightly poor body condition, with a mild generalized muscle atrophy and dull hair coat with multifocal alopecia, most evident on the ventral neck, abdomen and distal extremities. On closer inspection of the alopecic areas, there were abundant crusting, erosions and ulcerations of the skin, especially around the coronary bands and pastern on all four limbs. A moderate subcutaneous edema was evident on ventral abdomen and distal extremities. Free within the abdominal and thoracic cavity respectively, there were 2 liters of a straw-coloured transsudate. In the mucosa of the small intestine, large intestine and cecum, there were multifocal to coalescing, variably brownish coloured, round "button like" ulcers of approximately 0.5-4 cm in diameter, with elevated borders of firm consistency. The ulcers were often covered by light, dry, fibrinonecrotic material. There was also a diffuse, mild to moderate submucosal edema. In the non-glandular parts of stomach, there was severe hyperkeratosis. The liver was slightly decreased in size with a firm consistency, and on cut surface abundant fibrous streaks were evident, especially dissecting along bile ducts. The pancreas was moderately enlarged, firm in consistency and diffusely light in colour. Visceral and peripheral and lymph nodes varied from mildly to moderately enlarged, were slightly edematous, and varied in appearance; some showed distinct follicle formation and some were more homogenously light on cut surface. The bone marrow was light to dark red in colour.Laboratory Results:
N/AMicroscopic Description:
Haired skin, coronary band. Expanding and infiltrating the entire dermis are multifocal to coalescing perivascular, periadnexal and interstitial aggregates of moderate numbers of lymphocytes, eosinophils and histiocytes, fewer plasma cells and occasional neutrophils. Multifocally within dermis are few small areas of intensely eosinophilic, fragmented collagen fibers admixed with eosinophilic cellular- and basophilic nuclear debris, surrounded by epitheloid macrophages and multinucleated giant cells (eosinophilic granulomas). Intramurally and intraluminally within multiple hair follicles are moderate numbers of eosinophils, lymphocytes and histiocytes and few multinucleated giant cells (mural and luminal folliculitis), and adjacent follicular epithelium display moderate spongiosis. In the dermal-epidermal interface, there is a multifocal mild edema. The epidermis shows mild lymphocytic infiltration, mild spongiosis and occasional apoptotic keratinocyte, diffuse mild acanthosis and mild rete ridge formation (epidermal hyperplasia), moderate parakeratotic and orthokeratotic hyperkeratosis and multifocal erosions and ulcerations, the latter being covered by large serocellular crusts spanning over several adnexal units. Serocellular crusts show abundant viable and degenerated neutrophils, occasional eosinophil, cellular debris, fibrin, free keratin and hair fragments and occasional small basophilic bacterial colonies. There are also small epidermal intracorneal pustules multifocally. Several arteriolar walls in deep dermis show infiltration of few eosinophils and lymphocytes (vasculitis). The deep dermis displays mild diffuse edema.Contributor's Morphologic Diagnoses:
Haired skin, coronary band: Dermatitis and folliculitis, lymphoplasmacytic, histiocytic and eosinophilic, multifocal to coalescing, moderate, with eosinophilic granulomas, epidermal intracorneal pustules, serocellular crusts and orthokeratotic and parakeratotic hyperkeratosisEquine multisystemic eosinophilic epitheliotropic disease (MEED)
Contributor's Comment:
TBDContributing Institution:
Swedish University of Agricultural Sciences Department of Animal Biosciences, Section of Pathology Box 7023 SE 750 07, Uppsala, Swedenhttps://www.slu.se/enldepartments/Animal-Biosciencesf
JPC Diagnoses:
TBDJPC Comment:
TBDReferences:
- TBD
