Marko Hohšteter

A Case of Visceral Leishmaniosis in a Gray Wolf (Canis lupus) from Croatia

The southern habitats of Croatias gray wolf (Canis lupus) population are found in central and southern parts of Dalmatia. This region is recognized as an endemic region for canine visceral leishmaniosis, caused by Leishmania infantum. In November 2003, a 4-yr-old male gray wolf was found dead in the northwestern border of this endemic region. Pathologic and parasitologic analysis, confirmed by polymerase chain reaction, indicated that lesions associated with infection by Leishmania infantum are, in this case, typical for visceral leshmaniosis commonly described in dogs. Review of the literature suggests that this is the first reported case of gray wolf death due to lesions caused by L. infantum.

Disseminated tuberculosis in hyrax (Procavia capensis) caused by Mycobacterium africanum.

Abstract Tuberculosis due to Mycobacterium africanum was diagnosed in an adult female hyrax (Procavia capensis). Pathologic examination revealed disseminated tuberculous lesions. The same pathologic changes were also found in a male hyrax that died a year later. Both animals were imported from the United Arab Emirates and were held in captivity at the Zagreb Zoo in Croatia. The source of infection remains unknown. The acid-fast bacteria isolated from the lungs of the female hyrax were identifyed by polymerase chain reaction as Mycobacterium tuberculosis complex and Geno Type® MTBC test confirmed the strain to be M. africanum I.

Intratesticular benign peripheral nerve sheath tumour in a ferret (Mustela putorius furo)

A domestic ferret was submitted for sterilisation because of right testis enlargement. Oestradiol and cortisol concentrations were within normal physiological ranges, but testosterone was below and progesterone above normal. Microscopically, the right testis, with the exception of a small part of the epididymis, was replaced with neoplastic tissue. The tumour was composed of streams and bundles of closely packed spindle to ovoid cells forming whorls around collagen and capillaries, and separated by a collagenous matrix. In some areas, cells were loosely arranged and separated by a pale myxomatous matrix. The left testis showed atrophy. The majority of neoplastic cells expressed vimentin and S-100 protein, while expression of collagen IV was moderate and there was no expression of glial fibrillary acid protein. On the basis of macroscopical and histopathological findings, and supported by immunohistochemical reactivity, the diagnosis of benign peripheral nerve sheath tumour was made. This is the first report of benign peripheral nerve sheath tumour in ferret testis.

Complex mammary adenoma with sebaceous differentiation in a dog.

Sebaceous metaplasia arising within a complex adenoma of the left fourth mammary gland is described in a 9-year-old miniature pinscher bitch. Microscopically, the tumour was composed of tubular and ductular structures admixed with clusters of spindle-shaped, myoepithelial-like cells and units formed of well-differentiated sebocytes surrounded by basaloid cells. Abundant lipid droplets were identified within the latter population by Sudan III staining. Immunohistochemical expression of cytokeratin AE1/AE3 was detected in epithelial cells and in the cells with sebaceous differentiation.

IN VITRO CULTIVATION OF CANINE LIMBAL TRANSPLANT

Limbal epithelial stem cells are the ultimate source of regeneration of the entire corneal epithelium under both normal and injured conditions. The corneal epithelium plays a crucial role in homeostasis and integrity of the eye. To maintain the integrity of the ocular surface, corneal epithelial cells must be balanced by stem cells, located at the limbus. The limbus is the crossing area between the cornea and sclera, 1 mm in width, and together with conjunctival epithelium plays an important role in regenerating the cornea after traumatic injuries. The aim of this study was to evaluate the culturing patterns of canine limbal stem cells and to optimize growing conditions of these cell cultures in order to develop a reliable biomedical model intended for studying the potentials of allografts/xenografts originated from canine tissues. Canine stem cell equivalents have potentials in reparative/regenerative veterinary medicine.

Quantification of morphology of canine circumanal gland tumors: a fractal based study

Circumanal gland tumors are very common neoplasms of dogs. Their classification relies on microscopic examination and is further supported by a few immunohistochemical markers that help indicate their prognosis. However, new additional tests would be highly useful. The purpose of this study was to develop such a test using fractal analysis which is increasingly being applied in science, especially in the field of biomedicine. A total of 53 circumanal gland tumors were chosen from our department archives. After a precise histological classification according to the World Health Organization classification, the number of de novo classified samples was as follows: 15 adenomas, 11 epitheliomas, 21 well differentiated carcinomas, 6 poorly differentiated carcinomas. Ten samples of normal circumanal gland were also included as control. All samples were immunohistochemicaly stained with vimentin. All immunohistochemical reactions were photographed at two different magnifications -100X and 400X- and converted to 1 bit in black and white (bitmap) images, thus enhancing the positive vimentin reactions. These images were used for the assessment of fractal dimension applying the box counting method and computer software Fractalyse. To determine the significance of results, conventional statistics were performed using Statistica software. The overall vimentin stain score was significantly higher in epitheliomas and carcinomas than in normal circumanal glands (CG) or adenomas. Mean values of fractal dimension estimated at magnification 100X and 400X were as follows: normal CG 1.318 and 1.372, CG adenomas 1.384 and 1.408, CG epitheliomas 1.547 and 1.597, CG well differentiated carcinomas 1.569 and 1.607, CG poorly differentiated carcinomas 1.679 and 1.723. Significant differences (at level of 5%) of these values were observed between individual groups of CG adenomas or normal CG, and epitheliomas or carcinomas. The above results indicate vimentin immunohistochemistry staining and assessment of fractal dimension as an ancillary diagnostic method of choice when discerning between benign and malignant tumors of circumanal glands. Additional development of the method of fractal dimension assessment may yield a possibility for this tool to successfully discern between all of the types of CG tumors.

ECCRINE CARCINOMA IN THE FOOT OF AN ASIAN ELEPHANT (ELEPHAS MAXIMUS)

A case of eccrine carcinoma of the interdigital foot glands in a 39-yr-old female Asian elephant (Elephas maximus) from Zagreb Zoo is described. The tumor between the toenails of the right forefoot was surgically removed 3 yr before postmortem examination (2003), and the histopathologic diagnosis was compound eccrine carcinoma characterized with glandular tubular and papillary proliferations, mild cellular pleomorphism, proliferation of the myoepithelial cells with mucoid secretions, and necrosis. Immunohistochemistry revealed strong immunoreactivity to S-100 protein, estrogen, and high-molecular weight cytokeratin. This elephant also had chronic renal fibrosis with uremia.