Nasal osteoma in a dairy cow: a combined clinical, imaging and histopathological approach to diagnosis.

An 8-year-old Brown Swiss dairy cow was presented with unilateral epistaxis and mild inspiratory stridor. At that time endoscopic examination revealed a smooth-surfaced mass within the left nasal cavity. Biopsy samples were collected and a diagnosis of fibrosarcoma was made. Eighteen months later the animal developed severe respiratory distress that led to difficulties in feeding and consequently to emaciation and a dramatic drop in milk production. The cow was humanely destroyed and submitted for post-mortem examination. The head was subject to further investigation by radiography, computed tomography and magnetic resonance imaging. These techniques revealed a non-infiltrative, well-circumscribed mass of both radiodense and heterogeneously intense structures. Histopathological examination revealed a mass consisting of well-differentiated and interlacing bone trabeculae lined by osteoblasts and multinucleated osteoclasts. In contrast to the initial diagnosis, the later diagnostic approaches supported the diagnosis of osteoma.

Lawsonia intracellularis proliferative enteropathy in a filly.

Proliferative enteropathy (PE) caused by the obligate intracellular bacterium Lawsonia intracellularis is a disease of high economic impact in swine worldwide. In most other species the disease occurs as a sporadic infection. This paper reports a PE caused by L. intracellularis in a 9-month-old Pura Raza Española filly with a history of profuse diarrhoea. Pathological lesions consisted of a severe proliferative enteritis associated with argyrophilic bacteria in the apical cytoplasm of proliferating crypt epithelium. Characteristic PCR products confirmed the presumptive diagnosis of L. intracellularis infection. To our knowledge this is the first report of PE in a horse in Europe caused by L. intracellularis.

Immune dysregulation in flea allergy dermatitis--a model for the immunopathogenesis of allergic dermatitis.

BACKGROUND: Flea allergy dermatitis (FAD) is a common skin disease in dogs and can be induced experimentally. It often coexists with other allergic conditions. So far no studies have investigated the quantitative production of cytokine mRNA in skin biopsies and peripheral blood mononuclear cells (PBMC) in flea allergic dogs. OBJECTIVE: The aim of our study was to improve the understanding of the immunopathogenesis of allergic dermatitis as a response to fleabites. MATERIAL AND METHODS: Allergic and non-allergic dogs were exposed to fleas. Before and after 4 days of flea exposure mRNA was isolated from biopsies and PBMC. Production of chymase, tryptase, IL-4, IL-5, IL-13, TNF-alpha and IFN-gamma mRNA was measured by real-time RT-PCR. The inflammatory infiltrate in the skin was scored semi-quantitatively. The number of eosinophils, mast cells (MC) and IgE+ cells/mm2 was evaluated to complete the picture. RESULTS: FAD was associated with a higher number of MC before flea exposure and with a significant increase of eosinophils after flea exposure as compared to non-allergic dogs. The number of IgE+ cells was higher in allergic dogs before and after flea exposure. In allergic dogs mRNA for most cytokines and proteases tested was higher before flea exposure than after flea exposure. After exposure to fleas an increased mRNA production was only observed in non-allergic dogs. In vitro stimulation with flea antigen resulted in a decreased expression of most cytokines in allergic dogs before flea exposure. In contrast, in PBMC, only increased levels of IL-4 and IL-5 mRNA were observed in allergic dogs before flea exposure. However, after flea exposure and additional stimulation with flea antigen the production of mRNA for all cytokines tested was significantly increased in allergic dogs. CONCLUSION: We demonstrated that the response in biopsies and PBMC is different and that FAD is associated with a TH2 response.