Treponema spp. spirochetes and keratinopathogenic fungi isolated from keratomas in donkeys.

Keratoma is an aberrant keratin mass thought to originate from epidermal horn-producing cells interposed between the stratum medium of the hoof wall and the underlying third phalanx. The cause is unknown, although the presence of keratomas is frequently associated with chronic irritation, focal infection, or trauma. A total of 167 donkeys with keratomas were presented in this study. The diagnosis of a keratoma was based on clinical signs, radiography, and histopathologic examination. Surgical excision was attempted on all donkeys with lameness unless euthanasia was advised. Histopathologic examination, including Giemsa, periodic acid Schiff, and Young's silver special histochemical stains, was performed and showed the presence of fungal hyphae and spirochete bacteria within the degenerate keratin. Polymerase chain reaction (PCR) for treponeme bacteria was performed on 10 keratoma lesions and 9 healthy pieces of hoof (controls). All healthy donkey tissues were negative for the 3 recognized digital dermatitis (DD) treponeme phylogroups, whereas 3 of 10 (30%) donkey keratoma samples were positive for one of the DD treponeme phylogroups. Routine fungal culture and PCR for fungi were performed on 8 keratoma lesions and 8 healthy pieces of hoof (controls). Keratinopathogenic fungi were detected in 1 of 8 (12.5%) keratomas, while only non-keratinopathogenic, environmental fungi were detected in 8 control healthy hoof samples. This is the first time the DD treponemes phylogroup and keratinopathogenic fungi have been detected in keratomas. Further studies are required to assess the significance of this finding.

Identification of molecular genetic contributants to canine cutaneous mast cell tumour metastasis by global gene expression analysis.

Cutaneous mast cell tumours are one of the most common canine cancers. Approximately 25% of the tumours metastasise. Activating c-kit mutations are present in about 20% of tumours, but metastases occur in the absence of mutations. Tumour metastasis is associated with significantly diminished survival in spite of adjuvant chemotherapy. Available prognostic tests do not reliably predict whether a tumour will metastasise. In this study we compared the global expression profiles of 20 primary cutaneous mast cell tumours that metastasised with those of 20 primary tumours that did not metastasise. The objective was to identify genes associated with mast cell tumour metastatic progression that may represent targets for therapeutic intervention and biomarkers for prediction of tumour metastasis. Canine Gene 1.1 ST Arrays were employed for genome-wide expression analysis of formalin-fixed, paraffin-embedded biopsies of mast cell tumours borne by dogs that either died due to confirmed mast cell tumour metastasis, or were still alive more than 1000 days post-surgery. Decreased gene expression in the metastasising tumours appears to be associated with a loss of cell polarity, reduced cell-cell and cell-ECM adhesion, and increased cell deformability and motility. Dysregulated gene expression may also promote extracellular matrix and base membrane degradation, suppression of cell cycle arrest and apoptosis, and angiogenesis. Down-regulation of gene expression in the metastasising tumours may be achieved at least in part by small nucleolar RNA-derived RNA and microRNA-effected gene silencing. Employing cross-validation, a linear discriminant analysis-based classifier featuring 19 genes that displayed two-fold differences in expression between metastasising and non-metastasising tumours was estimated to classify metastasising and non-metastasising tumours with accuracies of 90-100% and 70-100%, respectively. The differential expression of 9 of the discriminator genes was confirmed by quantitative reverse transcription-PCR.

Canine soft tissue sarcoma managed in first opinion practice: outcome in 350 cases.

OBJECTIVE: To determine outcome of dogs with a diagnosis of soft tissue sarcoma managed in first opinion practice. STUDY DESIGN: Retrospective, case-controlled study ANIMALS: Dogs (n = 350) with primary occurrence of a soft tissue sarcoma. METHODS: A previously validated questionnaire was sent to all veterinarians requesting clinical information and ultimate outcome for all dogs. Histologic sections were reviewed by a single pathologist. RESULTS: Most surgeries were unplanned, with only 15 (4%) dogs having a histologic and 59 (16.8%) dogs having a cytologic diagnosis before surgery. Median survival time for all dogs was not reached with 70% proportional survival at 5 years. Local recurrence developed in 73 (20.8%) cases. The extent of resection performed was not associated with improved survival (P = .2) or tumor recurrence (P = .8). Age <8 years (χ(2) = 6.1; P = .01), tumors <5 cm in size (χ(2) = 9.6; P = .002) and discrete tumors (χ(2) = 16.6; P < .001) had improved survival outcomes. On multivariate analysis, a high tumor grade was significant for recurrence (HR 5.8; P < .001; 95% CI: 2.2-14.8). Evidence of a selection bias towards less aggressive tumors being managed in first opinion practice was confirmed. CONCLUSIONS: Wide resection margins are not the primary determinant of outcome for all soft tissue sarcoma. Veterinarians need to better understand the biologic behavior of a suspected soft tissue sarcoma before treatment to allow surgical margins to be adjusted accordingly.

A dermal melanoma in a young common seal (Phoca vitulina).

A subcutaneous melanocytic tumor was diagnosed during the rehabilitation period of a stranded 7-mo-old common seal (Phoca vitulina) suffering from parasitic bronchopneumonia. The clinical signs of the seal as well as the histopathology of the tumor are described. This is the first time a melanocytic tumor has been diagnosed in a common seal. The mass was identified as a low-grade dermal melanoma.

A case of fatal systemic toxoplasmosis in a cat being treated with cyclosporin A for feline atopy.

Acute systemic toxoplasmosis was diagnosed in a 4-5-year-old, male, Domestic Short Hair cat, which had been on cyclosporine A immunomodulatory therapy for feline atopy, over an 8-month period. Cyclosporin A (CsA) has shown promising results as a immunosuppressive agent in the cat for the treatment of eosinophilic plaque and granulomas, allergic cervico-facial pruritus, feline atopy and other immune-mediated dermatoses. However, inhibition of T-lymphocyte function by CsA is believed to have predisposed this cat to the development of a newly acquired, acute Toxoplasma gondii infection, as characterized by severe hepatic and pancreatic pathology in conjunction with the heavy parasite load demonstrated on immunohistochemical (IHC) stains for T. gondii. Cats on CsA therapy appear to be at risk of developing fatal systemic toxoplasmosis.

A case of metabolic epidermal necrosis in a cat.

Abstract This report describes clinical, histological and post-mortem findings in a cat, that are similar to necrolytic migratory erythema in humans and to metabolic epidermal necrosis in dogs. Resumen Este articulo describe los hallazgos clinicos, histopatológicos y post mortem en un gato, similares a Eritema Necrolitico Migratorio en la especie humana y a Necrosis Epidérmica Metabólica en el perro. [Patel, A., Whitbread, J., McNeil. P. A case of metabolic epidermal necrosis in a cat. (Un caso de necrosis epidérmica en un gato.) Veterinary Dermatology 1996; 7: 221-226.] Résumé Ce cas décrit les lésions cliniques, histopathologiques et nécropsiques chez un chat, évoquant l'érythème nécrolytique migrant de l'homme et la nécrose épidermique métabolique du chien. [Patel, A., Whitbread, J., McNeil. P. A case of metabolic epidermal necrosis in a cat. (Un cas de nécrose épidermique métabolique chez un chat.) Veterinary Dermatology 1996; 7: 221-226.] Zusammenfassung Dieser Bericht beschreibt klinische, histopathologische und Sektionsbefunde bei einer Katze, die dem hekrolytischen migratorischen Erythem beim Menschen und der stoffwechselbedingten epidermalen Nekrose beim Hund ähneln. [Patel, A., Whitbread, J., McNeil. P. A case of metabolic epidermal necrosis in a cat. (Ein Fall von stoffwechselbedingter epidermaler nekrose bei der Katze) Veterinary Dermatology 1996; 7: 221-226.].

Epidermotropic Cutaneous T-Cell Lymphoma (mycosis fungoides) in Syrian Hamsters (Mesocricetus auratus). A Report of Six Cases and the Demonstration of T-Cell Specificity.

Abstract- Epidermotropic cutaneous T-cell lymphoma was diagnosed in six Syrian hamsters (Mesocricetus auratus) with a generalised dermatosis characterised by pruritus, alopecia and exfoliative erythroderma. Plaques and nodules were evident in one animal. Clinical and histopathological findings were suggestive of mycosis fungoides and electron microscopical investigations in one case were supportive. Immuno-histochemical stains for CD3 antigen were strongly positive in all cases. Résumé- Un lyphome T cutané a été diagnostiqué chez six hamsters de Sibérie (Mesocricetus auratus) avec une dermatose généralisée, caractérisée par un prurit, une alopécle et une érythrodermie exfoliative. Des plaques et des nodules ont été observées sur un animal. Les données cliniques et histopathologiques étaient évocatrices d'un mycosis fungoïdes et les examens en microscopie électronique étaient compatibles dans un cas. Les marquages immuno-histochimiques de l'antigène CD3 étaient très positifs dans tous les cas. Zusammenfassung- Bei sechs Syrischen Goldhamstern (Mesocricetus auratus) wurde ein epidermotropes kutanes T-Zell-Lymphom mit einer generalisierten Dermatose diagnostiziert, die durch Pruritus, Alopezie und eine exfoliative Erythrodermie gekennzeichnet war. Bei einem Tier traten auch Plagues und Knoten auf. Die klinischen und histopathologischen Befunde deuteten auf Mycosis fungoides hin. Elektronenmikroskopische Untersuchungen unterstützten diesen Verdacht in einem Fall. Immunhistochemische Färbungen auf CD3-Antigen waren bei alien Fallen stark positiv. Resumen En un grupo de seis hamsters de siria, (Mesocricetus auratus), se diagnosticó limfoma epidermotrópico cutáneo de linfocitos T, presentando una dermatosis generalizada de tipo pruriginoso, acompañada de alopecia y eritroderma exfoliativo. Las placas y nódulos fueron evidentes en uno de los animales. Los estudios clinicos e histopatológicos indicaron una micosis fungoide, y las investigaciones de microscopía, en uno de los caseos, pareció indicar lo mismo. La tintura inmuno-histoquimica para el antígeno CD3 resultó claramente positiva en todod los casos.