Case No. 9; slide No. 146

Histological findings  Severe periadnexal infiltration with histiocytes, lymphocytes, neutrophiles and lesser plasma cells and mast cells  Multifocally severe granulomatous infiltration composed of neutrophils and macrophages with lesser lymphocytes oriented around free hair shaft (furunculosis)  Abundant small, 5µm in diameter (fungal spores) around and many hyphae in hair shafts  Mild lymphocytic infiltration into follicular wall  Multifocally nuclear debris within infundibula

Histological findings Moderate irregular epidermal hyperplasia Superficial perivascular infiltrate with mainly mast cells and lymphocytes Focally intracorneal crust

Morphological diagnoses Severe pyogranulomatous furunculosis and perifolliculitis with abundant intralesional fungal spores and hyphae

Aetiological diagnosis /Furunculosis

Disease Case No. 9; Slide No. 146  Poodle „Argo“  4 month, male  Round, plaque-like scaling lesions on neck and rump  No pruritus  Treatment locally with Miconazol shampoo and Chlorhexidine  No response to therapy

Silvia Rüfenacht, Dermavet, Oberentfelden Silvia Rüfenacht, Dermavet Infectious Causes of Folliculitis Demodex  Bacteria: . Staph. pseudintermedius  : . Microsporum spp. . spp.  Parasites: . Demodex spp. Differentiating features Fungal folliculitis / furunculosis . Cats: mild mural folliculitis, abundant fungi, . Dogs:mural folliculitis but may get luminal furunculosis, often few fungi Bacterial folliculitis / furunculosis . Luminal folliculitis, rare in cats Demodectic folliculitis / furunculosis . mural folliculitis, sebaceous glands may be involved, rare to abundant mites luminal folliculitis / furunculosis, Case No. 10; slide No. 173

Histological findings  Severe multifocal epidermal necrosis and ulceration  Necrosis involves follicular infundibulum and focally also the isthmus  In the necrotic epithelium and also in the epithelium adjacent to the necrosis multiple lightly basophilic to amphophilic large intranuclear inclusion bodies with margination of chromatin  Severe diffuse dermal infiltration of mainly eosinophils and fewer mast cells and histiocytes  Multifocally large areas of dermal necrosis including hair follicles Morphological diagnoses

Severe, acute, multifocal necrotizing and ulcerative dermatitis and folliculitis with intranuclear inclusion bodies

Severe, acute, superficial perivascular to diffuse eosinophilic and mastocytic dermatitis with multifocal extensive dermal necrosis

Case No. 10; slide No. 173

DSH „Nero“ 2 years, male castrated Ulcerative lesions on the nose Also small crusts in the temporal region and the base of the left ear Treated with Cefacat and Prednisolon for 10 days Worse after therapy No pruritus  Dr. W. Armbrust  Dr. Ottenjahn

Name of the disease Feline herpesvirus-induced ulcerative dermatitis

Differential Diagnoses Mosquito bite hypersensitivity Eosinophilic Plaque Food allergy Notoedres (Feline cowpoxvirus infection)

Typical clinical features

 Erosions and ulcerations on the face  Usually unilateral  Lesions on other body regions have been seen  Severity variable  Adherent crusts  Lymphadenopathy may be present  All ages

Aetiology

Feline Herpesvirus 1

Pathogenesis  Feline herpesvirus 1 infection  History of upper respiratory infection  Latency of virus in trigeminal ganglia proposed