August 2019

Signalment (JPC# 2155783):  Female rabbit (Oryctolagus cuniculus)

HISTORY:  Genital lesion

HISTOPATHOLOGIC DESCRIPTION: Mucocutaneous junction, vulva (2 sections): Diffusely the epidermis is hyperplastic, thickened up to 3 times normal, characterized by acanthosis, anastomosing rete ridges, intercellular clear spaces with prominent intercellular bridging (spongiosis), and intracellular edema.  There are multifocal erosions and ulcerations with replacement by a serocellular crust composed of necrotic cellular and karyorrhectic debris admixed with serum, numerous degenerate heterophils, lymphocytes, and variably sized colonies of 2 um diameter basophilic cocci.  Within the adjacent epithelium there is ortho- and rare parakeratotic hyperkeratosis.  The superficial dermis is infiltrated by moderate numbers of macrophages, heterophils, and fewer lymphocytes and plasma cells that surround adnexa and blood vessels, transmigrate the epidermis and follicular epithelium (exocytosis), and infiltrate follicular lumens (folliculitis).  Hair follicles are multifocally dilated and filled with lamellations of keratin.  Multifocally within the superficial dermis there is hemorrhage, fibrin, and increased clear spaces and ectatic lymphatics (edema). The inflammation extends into the deep dermis and panniculus carnosus muscle, surrounding, separating, and individualizing skeletal myocytes which are often shrunken and hypereosinophilic (atrophy).

MORPHOLOGIC DIAGNOSIS:  Mucocutaneous junction (vulva):  Dermatitis and folliculitis, suppurative and lymphoplasmacytic, diffuse, moderate, with epidermal hyperplasia, orthokeratosis, ulceration, and superficial mixed population of bacteria, breed not specified, lagomorph.

ETIOLOGIC DIAGNOSIS: Cutaneous treponemiasis

CAUSE: Treponema paraluiscuniculi (formerly T. cuniculi)

CONDITION:  Rabbit syphilis

SYNONYMS:  Venereal spirochetosis, vent disease, treponematosis










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