General comments
Clinical signs
This disease usually does not affect the face or head. Abdominal lesions are described, and it is a pruritic disease. Pustules, collarettes and papules are found.
Histopathology
The original description of this disease describes a combination of intraepidermal eosinophilic pustules, mural eosinophilic folliculitis and furunculosis. Other reported suggest nodules of eosinophils in the dermis not involving the follicles. The intraepidermal and follicular pustules may have acantholytic cells in them. There is a suggestion that intraepidermal pustules are not always present.
Differential diagnosis
Eosinophilic furunculosis of the face
Pemphigus foleaceous
Comments
It appears that this condition may be a combination of eosinophilic vesiculopustular disease, nodular eosinophilic disease or eosinophilic furunculosis. It does not have to have all 3.
Scott DW. Sterile eosinophilic pustulosis in dog and man: Comparative aspects.
Neospora caninum
Neosporiosis is uncommon in dogs and infection of the skin as a primary disease is not reported. It is reported as a cutaneous manifestation of systemic disease. Dogs are usually in an altered immunocompetent state. Occasionally, immunocompetent dogs are affected.
The gross lesions are 2 to 10 cm nodules that often rupture and release serosanguinous fluid. They are in the dermis and panniculus anywhere on the body.
Histologically, the lesions are nodular, in the dermis and panniculus and frequently have a necrotic center. Neutrophils and macrophages surround these necrotic foci. Organisms are usually visible on routine sections and immunohistochemistry is helpful for better identification.
Decôme M, Martin E, Bau-Gaudreault L, O'Toole E. Systemic disseminated Neospora caninum infection with cutaneous lesions as the initial clinical presentation in a dog. Can Vet J. 2019; 60: 1177-1181.