Red mark syndrome (RMS) is a skin disorder affecting rainbow trout (Oncorhynchus mykiss). The present work aimed to correlate the gross skin lesions affecting 46 fish sampled from farms surveyed for RMS with their microscopic features, identifying histological parameters that may be suggestive of disease progression. Skin lesions were grossly included in one of three categories (types I, II and III) according to the progressive degree of severity. Histological parameters and anti-proliferating cell nuclear antigen (PCNA) tissue immunoreactivity were semi-quantitatively assessed. In the dermis, PCNA-positive lymphocytes, fibroblasts and endothelial cells were indicative of active phlogosis. A significant increase in PCNA-immunoreactive lymphocytes, from gross type I to type III cases, was found only in the hypodermis. The histological parameters significantly associated with the gross lesion severity were progressive loss of the epithelium and scales, recruitment of inflammatory cells in the stratum compactum, loss of architecture of the stratum compactum, perivascular and perineural granulomatous inflammation and increase in lymphocyte infiltration of the muscular layer. In the type II and type III categories, inflammation in the hypodermis and muscle displayed a granulomatous pattern, reinforcing the hypothesis of an immunopathological mechanism. The morphological diagnosis of "deep chronic dermatitis associated to panniculitis and myositis, characterised by lympho-histiocytic and granulomatous reaction" is suggested.

Journal of Fish DiseasesVolume 40, Issue 12 p. 1935-1939 SHORT COMMUNICATION First report of Red Mark Syndrome (RMS) in farmed rainbow trout in Slovenia M Galeotti, Corresponding Author M Galeotti marco.galeotti@uniud.it orcid.org/0000-0003-1378-8135 Veterinary Pathology Section, DI4A, University of Udine, Udine, Italy Correspondence Marco Galeotti, Veterinary Pathology Section, DI4A, University of Udine, Udine, Italy. Email: marco.galeotti@uniud.itSearch for more papers by this authorP Ronza, P Ronza orcid.org/0000-0003-0180-0715 Departamento de Anatomía, Producción Animal y Ciencias Clínicas Veterinarias, Universidad de Santiago de Compostela, Santiago de Compostela, SpainSearch for more papers by this authorP Beraldo, P Beraldo Veterinary Pathology Section, DI4A, University of Udine, Udine, ItalySearch for more papers by this authorC Bulfon, C Bulfon Veterinary Pathology Section, DI4A, University of Udine, Udine, ItalySearch for more papers by this authorG E Magi, G E Magi School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, ItalySearch for more papers by this authorM Manzano, M Manzano Microbiology section, DI4A, University of Udine, Udine, ItalySearch for more papers by this authorD Volpatti, D Volpatti Veterinary Pathology Section, DI4A, University of Udine, Udine, ItalySearch for more papers by this author M Galeotti, Corresponding Author M Galeotti marco.galeotti@uniud.it orcid.org/0000-0003-1378-8135 Veterinary Pathology Section, DI4A, University of Udine, Udine, Italy Correspondence Marco Galeotti, Veterinary Pathology Section, DI4A, University of Udine, Udine, Italy. Email: marco.galeotti@uniud.itSearch for more papers by this authorP Ronza, P Ronza orcid.org/0000-0003-0180-0715 Departamento de Anatomía, Producción Animal y Ciencias Clínicas Veterinarias, Universidad de Santiago de Compostela, Santiago de Compostela, SpainSearch for more papers by this authorP Beraldo, P Beraldo Veterinary Pathology Section, DI4A, University of Udine, Udine, ItalySearch for more papers by this authorC Bulfon, C Bulfon Veterinary Pathology Section, DI4A, University of Udine, Udine, ItalySearch for more papers by this authorG E Magi, G E Magi School of Biosciences and Veterinary Medicine, University of Camerino, Camerino, ItalySearch for more papers by this authorM Manzano, M Manzano Microbiology section, DI4A, University of Udine, Udine, ItalySearch for more papers by this authorD Volpatti, D Volpatti Veterinary Pathology Section, DI4A, University of Udine, Udine, ItalySearch for more papers by this author First published: 26 May 2017 https://doi.org/10.1111/jfd.12652Citations: 11Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume40, Issue12December 2017Pages 1935-1939 RelatedInformation

Leishmania, an intracellular protozoan parasite, is endemic, widespread and represents a public health problem in most countries of the Mediterranean basin as it is implicated in a wide spectrum of diseases both in humans and animals. Vaccination of canines remains the best control strategy to counteract the progression of active infection for canine disease in areas of the world where transmission to humans is primarily zoonotic. This case report describes the history of a four-year-old dog vaccinated against canine leishmaniosis that was presented to a private clinic for the onset of a nodular skin lesion. Besides normal haematological and biochemical analyses, the histopathological examination of the removed skin lesion revealed the presence of Leishmania amastigotes. The presence of the protozoa in the skin lesion of a vaccinated dog is discussed.

Red mark syndrome (RMS) and US strawberry disease (US SD) are skin disorders affecting rainbow trout farmed in Europe and USA. The disease etiology has not yet been established. In spite of specific investigations, identifying Rickettsia-like organism (RLO)- and Midichloria-like organism (MLO)-related DNA in affected individuals, these pathogens have never been observed. We performed histological, ultrastructural and biomolecular analysis on skin and spleen samples of trout with RMS. Examination by TEM revealed the presence of intracytoplasmic microorganisms resembling Rickettsiales within macrophages, fibroblasts and erythrocytes. The microorganisms were oval or short rod shaped (400-800 nm in length and 100-200 nm in width) and often showed a cell wall similar to Gram-negative bacteria. PCR analysis for Rickettsiales supported these findings: 53% of affected trout were positive by both PCR and TEM The primers RiFCfw-RiFCrev were used to anneal both the RLO 16S DNA sequence and the MLO 16S DNA sequence. For this reason, and in agreement with previous studies confirming the presence of Rickettsiales-related DNA in trout with RMS, we assume that TEM detected microorganisms morphologically consistent with bacteria belonging to Rickettsiales order and could be considered as possible causative agents of RMS.

INTRODUCTION: CD25 (IL-2Ra) is the α-subunit of the membrane-bound interleukin-2 receptor (IL-2R), which is mainly expressed by regulatory T cells (Tregs). Tregs play a pivotal role in the homeostasis of the immune system and in the modulation of the immune response (1,2). Two type of Tregs are known: natural Treg and adaptive Treg. Normally these cells regulate immune system activity and prevent autoimmunity. Imbalanced function or number of these cells, either enhanced or decreased, might lead to tumor development and autoimmunity, respectively (1,2,3,4). In the present study we hypothesized the presence of CD25+ cells among tumor infiltrating lymphocytes (TILs) that are normally associated with feline injection-site sarcoma (FISS), a type of tumor considered a good model to study a link between inflammation and neoplasia. To this end the CD25 protein expression levels were analyzed by immunohistochemistry in eighteen cases of FISS and in 15 cases of post-injection panniculitis (PIP).

A Carrassius auratus auratus presented for a mass diagnosed as a fibrosarcoma. It was anaesthetised and an electrosurgical device was used and the mass was ablated. There is no previous documentation for electrocautery use in fish oncology. This note provides a safe protocol for electrosurgical excision of neoplasia in fish.

Visna/Maedi virus (VMV), a small ruminant lentivirus responsible for lymphoproliferative pneumonia, encephalitis, arthritis and/or mastitis in sheep, has been detected in different non-lymphoid organs. However, only a few investigations have been carried out in lymphoid tissues. In this study, some lymphoid tissues and lymph node draining or non-draining VMV target organs from five sheep infected experimentally by the respiratory route three years previously were investigated. Archival samples of spleen, red bone marrow, caudal mediastinal lymph nodes, mammary lymph nodes, popliteal lymph nodes and mesenteric lymph nodes were tested by PCR for the presence of proviral DNA. Popliteal and mesenteric lymph node samples were tested also by immunohistochemical staining of the viral capsid antigen p28. The proviral DNA was detected by PCR in all the lymphoid tissue samples from the infected sheep. The viral antigen was stained in mononuclear cells in popliteal and mesenteric lymph nodes of the infected sheep. Although the lymph nodes draining the classical target organs seem to be more infected than the others, both the viral capsid antigen and the proviral DNA were present also in lymph nodes draining non-target organs, such as the mesenteric lymph nodes. These findings show the presence of VMV in different lymphoid tissues in the late stages of infection and suggest a potential role of these tissues as a site for viral reservoir and replication, even three years after infection.

Paratuberculosis is a widespread disease of ruminants caused by Mycobacterium avium subspecies paratuberculosis (MAP). For long time the infection has been believed as confined to the intestine. Disseminated infection in ruminants with MAP has gained more interest in recent years. In this study the histological lesions, the distribution of MAP in intestinal and mammary tissues of seropositive sheep and the sensitivity of direct diagnostic tests are evaluated. Histopathological lesions were observed in the proximal jejunum, distal jejunum and ileum of 19 sheep. Types 3b and 3c lesions were observed. Sheep with subclinical infection had type 3c Heal lesions, while clinically infected animals had mainly type 3b Heal lesions (p < 0.05). Ziehl-Neelsen (ZN) staining was more sensitive for detecting acid-fast bacilli in type 3b intestinal lesions than in type 3c (p < 0.05). Immunohistochemistry (IHC) was more sensitive than ZN staining in detecting infected intestinal samples (p < 0.05). PCR was the most sensitive technique in detecting MAP in both intestinal and extra-intestinal samples (p < 0.05). MAP was mainly observed in mammary tissues of sheep with type 3b intestinal lesions, although these findings were not statistically significant (p > 0.05). The number of MAP in the intestine might influence the clinical course and the local histopathological lesions, but probably further factors contribute to the discrimination between local and general infection. (C) 2011 Elsevier B.V. All rights reserved.