MICROSCOPICAL BRAIN LESIONS IN DOGS WITH VISCERAL LEISHMANIASIS G.D. Melo * , F.G. Grano * , J.E.S. Silva * , J.M. Silva * , A. Schweigert * , A.T. Ramos y , I.M. Langohr z and G.F. Machado * * S~ao Paulo State University (UNESP), College of Veterinary Medicine, Laboratory of Applied Pathology, Arac¸atuba, SP, y Federal University of Santa Catarina, School of Veterinary Medicine, Curitibanos, SC, Brazil and z Michigan State University, College of Veterinary Medicine, Department of Pathobiology and Diagnostic Investigation, East Lansing, MI, USA Introduction: Visceral leishmaniasis (VL) is caused by the zoonotic protozoan Leishmania chagasi (synonymous with L. infantum). In dogs, there is frequent association of chronic VL with neurological lesions, but descriptions of specific brain alterations are lacking. Therefore, we aimed to characterize the histopathological changes in the brain of dogs infected naturally by L. chagasi. Materials and Methods: Brain samples from 40 infected dogs including the telencephalon, diencephalon and metencephalon were paraffin wax-embedded, sectioned and stained with haematoxylin and eosin. The slides were evaluated by light microscopy. Results: The most common lesions were mild to marked meningitis (77.5%), choroiditis (74.2%), subventricular gliosis (72.5%) and lymphohistoplasmacytic perivascular cuffs (55.0%). Glial nodules (30.0%) and satellitosis/neuronophagia (32.5%) were also detected. Additionally, there was vascular congestion (52.5%) and microhae- morrhage (40.0%). Conclusions: The frequent occurrence of microscopical alterations in the brain of infected dogs supports previous evidence that the ner- vous system is affected during VL. The observation of lesions mostly at the meningeal and ventricular surfaces suggests a response to pe- ripheral infection, possibly after interaction of glial cells with leish- manial components or inflammatory cells and mediators in blood and cerebrospinal fluid, respectively. CUTANEOUS MYCOBACTERIUM AVIUM COMPLEX INFECTION IN CATS ORIGINATING FROM THE ISLAND OF HVAR, CROATIA A. Beck * , S.  Spicic y , I. Racic y , I.C.  Sostaric-Zuckermann * , A. Gudan Kurilj * ,  Z. Grabarevic * ,  Z. Cvetnic y and R. Beck y * Department of Veterinary Pathology, Veterinary Faculty, University of Zagreb and y Croatian Veterinary Institute, Department for Bacteriology and Parasitology, Zagreb, Croatia Introduction: Cutaneous granulomas of cats are rarely caused by culti- vable saprophytic mycobacteria from the Mycobacterium avium complex (MAC). MAC skin infection has non-specific cutaneous nodular presen- tation and three histomorphological forms: granulomatous, pyogranu- lomatous and spindle cell. We present four cases of MAC-induced skin granulomas in cats originating from the seaport of the island of Hvar. Materials and Methods: In three cases submitted as skin tumours we diagnosed granulomatous inflammation and presumed feline lepromatous leprosy based on granuloma architecture. In the fourth case, feline leprosy was suspected based on an impression smear finding of negatively-stained intracellular bacilli taken from an ulcer- ated nodule. Mycobacterial culture was performed from the granu- loma tissue of two cats. DNA was extracted from formalin-fixed and paraffin wax-embedded tissue and from fresh tissue. A partial fragment of 16S rRNA was amplified and subsequently sequenced and compared with sequences in GenBank. Routine histology and Ziehl-Neelsen staining were performed in the fourth case. Results: Mycobacteria were not detected by culture after 12 weeks of incubation. In the first three cases the granuloma architecture was rich in foamy macrophages and multinucleate giant cells harbouring high numbers of slender acid-fast bacilli. Organisms were numerous within spindle cells in the fourth case with typical MAC spindle cell proliferation. All sequences were identical. They revealed 100% identity with sequences of MAC members. Conclusions: Mycobacteria growth characteristics on synthetic me- dia, as well as the histological pattern of skin granulomas, are not suf- ficient to distinguish different bacterial species, indicating the importance of molecular typing. EVIDENCE FOR THE ROLE OF A SHREW SPECIES AS A RESERVOIR HOST OF BORNA DISEASE VIRUS IN EASTERN GERMANY H. Weissenb€ ock * , R. D€ urrwald y , J. Kolodziejek z and N. Nowotny z * Institute of Pathology, z Institute of Virology, Vetmeduni Vienna, Austria and y IDT Biologika GmbH, Dessau-Roßlau, Germany Introduction: Borna disease (BD) is a sporadic viral neurological disease of several mammalian species, predominantly horses. Recently, Swiss researchers identified the bicoloured white-toothed shrew (Crocidura leucodon) as a potential vector species. The aim of this study was to evaluate whether Borna disease virus (BDV)-in- fected shrews are present in a different endemic region for BD, Eastern Germany. Materials and Methods: During five consecutive years (2005e2010) 106 shrews of four different species (among them 55 C. leucodon) were collected in several Eastern German federal states. After necropsy examination, samples were processed for histology, BDV immunohistochemistry (IHC) and RT-PCR. Results: In twelve (21.8%) C. leucodon shrews BDV genomic RNA was detected by RT-PCR. In the absence of histological lesions IHC showed strong expression of BDV proteins in many neural and extraneural tissues, suggesting a persistent infection. In other shrew species BDV was not detected. The same BDV strain was iden- tified in these shrews, and this differed from the BDV strain obtained from the Swiss shrews. Conclusions: These observations show that territorially restricted distinct BVD strains cause persistent, subclinical infections in C. leuco- don shrews. The widespread organ tropism suggests shedding of the vi- rus by different routes and confirms the potential role of C. leucodon as a reservoir host and source of transmission to susceptible mammalian species. MICROARRAY ANALYSIS OF CANINE DISTEMPER VIRUS- INDUCED DEMYELINATING LEUCOENCEPHALITIS R. Ulrich * , C. Puff * , K. Wewetzer y , A. Kakuhl z , U. Deschl z and W. Baumg€ artner * * Department of Pathology, University of Veterinary Medicine Hannover, y Department of Functional and Applied Anatomy, Center of Anatomy, Hannover Medical School and z Department of Non-Clinical Drug Safety, Boehringer Ingelheim Pharma, Biberach (Riß), Germany Introduction: Distemper is a systemic viral infection of dogs causing pneumonia, gastroenteritis, lymphopenia and encephalomyelitis. Canine distemper virus (CDV)-induced demyelinating leucoence- phalitis (CDV-DL) in dogs is a translational animal model for multi- ple sclerosis. The aim of this study was to perform an assumption-free microarray analysis of transcriptional changes in CDV-DL. Materials and Methods: RNA was isolated from the cerebellum of three to six dogs per subgroup of CDV-DL and 12 normal control dogs and hybridized to canine genome 2.0 arrays (Affymetrix). Data were normalized employing GC-RMA and differential expres- sion was identified employing LIMMA (q 0.05) and a fold change filter (-2 or 2). Results: Microarray analysis revealed 442 differentially expressed genes. The dominant change was constant up-regulation of genes related to responses to other organisms and wounding, and the hu- moral and cell-mediated immune responses. Multiple myelin genes were down-regulated at the onset of demyelination, followed by a rebound in later stages. Notably these later stages exhibited a unique up-regulation of gd T lymphocyte and immunoglobulin marker genes. Conclusions: The transcriptional changes suggest a biphasic mode of demyelination in CDV-DL with an initial oligodendropathy fol- lowed by a second wave of intrathecally-produced immunoglobulin- mediated autoimmunity. 82 ESVP/ECVP Proceedings 2013 150:1, 2014