Osteosarcoma in a free-living yellow armadillo (Euphractus sexcinctus).

An adult male free-living yellow armadillo (Euphractus sexcinctus) was found by hunters and referred for clinical evaluation because of a tumour-like lesion on the carapace. The animal was lethargic and weak with severe dehydration, enophthalmos and cachexia, and was euthanized because of its very poor clinical condition. Necropsy revealed a whitish, exophytic, irregular and moist mass (7 × 6.5 × 1.5 cm) in the caudal third of the carapace. On cut section, the mass was hard, compact, irregular and whitish. Histopathology revealed a densely cellular, expansive, poorly delimited neoplasm composed of malignant mesenchymal cells arranged in islands and cords, interspersed by numerous areas of irregularly mineralized osteoid matrix. Neoplastic cells were intensely immunolabelled for vimentin. The diagnosis of a high-grade osteosarcoma of osteoblastic subtype was based on the clinical, gross, histopathological and immunohistochemical findings. This first report of an osteosarcoma in an armadillo expands the list of armadillo diseases and will assist the management of these animals by veterinarians.

Prevalence and anatomopathological characterization of cutaneous squamous cell carcinomas with regional and distant metastases in dogs and cats: 20 cases (1985-2020).

The aim of this study was to assess the prevalence of regional and distant metastases from cutaneous squamous cell carcinomas (SCCs) in dogs (n = 11) and cats (n = 9) in a retrospective case series over 36 years (1985-2020), as well as to characterize its macroscopic aspects (location and size), degree of differentiation (well, moderately and poorly differentiated [WD, MD and PD, respectively]) and the rate of cell proliferation, by counting the AgNORs. Immunohistochemistry (IHC) was used to identify patterns of tumour migration and invasion (islands, ribbons, cords, small aggregates, individual cells [fusiform and amoeboid]) and to evaluate the intensity of desmoplasia and the amount of myofibroblasts. The prevalence of metastatic SCCs was 4.39% (21/478), being 3.8% in dog (12/309) and 5.3% in cat (9/169). Metastases affected lymph nodes in all dogs and 66% (6/9) of cats, and less frequently distant organs. Primary tumours predominantly affected the abdominal skin in dogs and the nasal planum in cats. Among the 20 cases, 52% were MDs, 34% were WDs, and 14% were PDs. Histological lesions suggestive of exposure to chronic solar radiation were present in 57% (8/14). The main patterns of tumour migration and invasion were islands for WD SCCs and individual cells for PD SCCs. MD SCCs had a mix of patterns. In cats, individual spindle cells were restricted to PDs. A marked desmoplastic reaction was more associated with PD SCCs and often with MDs. This study highlights that the prevalence of SCC metastases in dogs and cats is predominantly regional. The IHC was essential in the identification of individual fusiform keratinocytes, whose presence in surgical margins may represent a greater risk of recurrence. Although the presence of myofibroblasts was observed in all infiltrative and metastatic tumours, further studies evaluating these cells may be important to better understand their role in the tumour microenvironment of cutaneous SCCs with metastasis in dogs and cats.

A Retrospective Study of Pythiosis in Domestic Animals in Northeastern Brazil.

Pythiosis is an endemic disease in northeastern Brazil and we now report the epidemiological, clinical and pathological findings in a retrospective study of naturally occurring cases in domestic animals. From January 1985 to December 2020, the Laboratory of Animal Pathology of the Federal University of Campina Grande examined 13,542 tissue samples from necropsies and biopsies. Among these samples, 306 were diagnosed as pythiosis: 195 cases in horses, 75 in sheep, 19 in dogs, six in mules, four in cattle, three in cats, two in goats, one in a donkey and one in an ostrich. Affected equids had lesions in the skin, mammary glands and nasal cavities. Affected sheep had cutaneous, nasal and digestive lesions while cattle and goats had cutaneous lesions. Carnivores developed lesions, mainly in the alimentary tract, of sufficient severity to cause death or result in euthanasia. The single affected bird had lesions in the alimentary tract and surgical excision resulted in remission. The disease had a long and life-threatening clinical course in most affected species but resolved spontaneously in cattle. Clinical signs were directly related to the location of the lesions, which were invariably characterized by chronic inflammation associated with intralesional hyphae. Veterinary clinicians and pathologists should be familiar with the clinicopathological features of pythiosis and the wide range of susceptible animal species.

Effects of Heated Pneumoperitoneum on Inflammation, Oxidative Stress, and Peritoneal Histology in Female Dogs That Underwent Video-Assisted Ovariohysterectomy.

Laparoscopic procedures require the creation of pneumoperitoneum. CO2, which must be cold and dry, is the standard gas used in such surgeries. The type of gas used, its temperature, and moisture may change the peritoneal surface and cause systemic and local oxidative stress. Our objective is to evaluate the influence of pneumoperitoneum heating on the occurrence of histological lesions in the peritoneum, inflammation, plasma oxidative stress, and on the mesothelial surface in patients undergoing video-assisted ovariohysterectomy. Twenty canine females were included and distributed evenly into two groups: heated CO2 (HG) and unheated CO2 (UHG). The biomarkers of inflammation and oxidative stress were evaluated before insufflation (T0), at 30 min (T1), and at 60 min (T2) of exposure to CO2. Biopsies of the peritoneal tissue for histological evaluation were performed at T0 and T2. Regarding plasma parameters, acetylcholinesterase (AChE) showed a greater activity in the HG at T1 (p=0.0268) and T2 (p=0.0423); in turn, butyrylcholinesterase (BChE) showed a greater activity at T2 in the HG (p=0.0175) compared with T0. Catalase activity (CAT) was different between HG times; it was higher at T1 (p=0.0253). There was a decrease in the levels of substances reactive to thiobarbituric acid (TBARS) (p=0.0117) and in glutathione (GSH) (p=0.0114) between T0 and T2 in the UHG. Regarding tissue oxidative stress, the CAT in the HG showed a greater activity at T2 than T1 (p=0.0150). By comparing the groups at each time, there was a difference only at T2 (p=0.0288), being greater in the HG. Regarding the activity of superoxide dismutase (SOD) in the HG, there was a difference between T2 in relation to T0 and T1 (p=0.0181); finally, there was an increase only at T1 (p=0.0287) in the UHG when comparing groups at the same time. There were no differences in the histological parameters evaluated. Our study demonstrates that the heating of CO2 generates a greater inflammatory response and forms reactive oxygen species (ROS) at the plasma and peritoneal levels.

Acaricide activity of organo-modified siloxane and acaricide associations in Rhipicephalus microplus.

Search to a new alternative to control bovine ticks (Rhipicephalus microplus), the present study aimed to evaluate the acaricidal activity of organo-modified siloxane alone and in association with different commercial products or with piperonyl butoxide (BPO). Engorged females were subjected to an in vitro immersion test and 10 groups were used: control, 0.5% siloxane, 1% siloxane, 2% siloxane, 0.5% siloxane + 5% BPO, 1% siloxane + 5% BPO, 2% siloxane + 5% BPO, commercial product, 0.5% siloxane + commercial product, and 1% siloxane + commercial product. After immersion, engorged females were incubated for 14 days for oviposition and hatchability tests. Another immersion test was performed with 5% siloxane and 2.5% siloxane + 10% BPO to evaluate the histopathological changes. Then, engorged females were incubated for 0, 2, 4, 8, 12, 24, 36, 48, 60, 72, 84, 96, 120, 144, and 168 h and immersed in 10% formaldehyde for later analyses. The unassociated siloxane showed an acaricide efficacy of 93.88% at 2% concentration, and when associated with 5% BPO, it reached 100% efficacy at all tested concentrations. The tested commercial products showed enhanced efficacy when associated with siloxane. Histopathological analysis showed cell changes in both treatments and total cell disintegration after 120 h in the 5% siloxane group and after 96 h in the 2.5% siloxane + 10% BPO group. Therefore, siloxane alone or in combination is an alternative against R. microplus, and siloxane enhances the efficacy of available commercial products.

Pythiosis in Equidae in Northeastern Brazil: 1985-2020.

The epidemiologic, clinical, pathologic, microbiological and immunohistochemical findings of pythiosis in equidae in northeastern Brazil are described. From January 1985 to December 2020 the Laboratory of Animal Pathology of the Federal University of Campina Grande received 1,331 tissue samples of equidae, 202 (15.17%) of which were diagnosed as pythiosis. Equidae of both sexes with ages varying from 4 months to 25 years were affected. Most animals were mixed breed (79.7%) and reared in an extensive system (73.26%). The disease occurred throughout the year but the highest incidence (70.29%) was noted after the rainy season. The clinical course was always chronic. The lesions were preferentially located on the limbs and ventral thoracoabdominal wall and characterized by nodules or tumor-like masses with ulcerations and serosanguineous discharge. The cut surface showed fistulous tracts containing kunkers. The direct examination of the kunkers and microbiological culture revealed sparsely septate and branched hyaline hyphae. Histopathology revealed a marked inflammatory infiltrate of eosinophils with multifocal well-defined areas of eosinophil necrosis and collagenolysis and intralesional negatively-stained hyphal profiles; in the donkey, a pyogranulomatous inflammatory infiltrate was noted surrounding these areas. Immunohistochemistry for Pythium insidiosum revealed strong immunolabelling of the hyphae. Pythiosis occurs endemically in equidae in northeastern Brazil, with seasonal variation in the incidence. The intralesional kunkers establishes an accurate presumptive diagnosis, but confirmation should preferably be performed through histopathology associated with immunohistochemistry, culture-based or molecular methods.

Cartilage Degeneration of the Metacarpal Condyle and Enthesopaties of The Collateral Ligaments of Equine Metacarpophalangeal Joint.

Articular degeneration can be characterized by fibrillation and eburnation of the articular layers of the metacarpophalangeal (MP) joint. Structural changes within the articular joint predispose the development of osteophytes, enthesophytes and, in many cases is associated with changes the collateral ligaments of the MP joint. The aim of the present study was to investigate the relationship between degenerative processes of the articular cartilage and the enthesopathies of collateral ligaments (superficial or deep portion) of the equine MP joint, using radiographic, ultrasonographic and anatomopathological exam, as well as establishing their sensitivity. Thirty equine forelimbs were selected from animals that died due to various clinical conditions with an average age of 5.7 years which came from a private clinic or sent to the Laboratory of Veterinary Pathology of UFSM. The specimens were placed in a hydraulic press and submitted to radiographic evaluation of the MP joint (lateromedial, flexed lateromedial, dorsopalmar, dorsolateral-palmaromedial oblique 450 and dorsomedial-palmarolateral oblique 450 projections). Transversal and longitudinal ultrasound images of the dorsal and collateral aspect of the MP joint were obtained using a Sonosite Edge machine with a 5 to 10 MHz linear transducer. Subsequently, the specimens were sent for gross and histopathological examination. A highly positive correlation (P value <.001) was observed between ultrasonographic and macroscopic techniques, showing a relationship between the cartilaginous degenerations of the MP joint and the medial and lateral LC enthesopathies.

Non-Renal Lesions of Uraemia in Domestic Cats.

Uraemia is a clinical syndrome caused by an increase in uraemia-associated toxins in the bloodstream as a consequence of intrinsic kidney or lower urinary tract diseases. Cats seem to be more affected by urinary tract diseases than dogs, particularly considering that chronic kidney disease (CKD) is one of the most important conditions in cats. Considering the lack of information on the systemic lesions of uraemia in cats, the aim of this study was to investigate the prevalence and clinical and pathological aspects of non-renal lesions in uraemic cats, with special attention to the differences between cats and dogs. Cats necropsied between 2000 and 2019 (n = 1,330) were investigated for urinary tract diseases and non-renal lesions of uraemia. The prevalence of uraemic cats with non-renal lesions (n = 78) was 5.8%. Adult, elderly and male animals were predominantly affected. Anorexia, apathy and vomiting were the most common clinical signs and CKD was observed in the majority of uraemic cats. Pulmonary oedema was the most frequent non-renal lesion identified. In contrast with previous reports, haemorrhagic and ulcerative gastritis was frequently observed, whereas soft tissue mineralization and parathyroid hyperplasia were uncommon features. Fibrous osteodystrophy was not observed. Cats with urinary tract diseases did not have as wide a variety of non-renal uraemic lesions as uraemic dogs and multisystemic manifestation of uraemia was observed in only 24.4% of cases.

Myoepithelial cells and extracellular matrix in the cytologic differentiation of canine mammary tumors.

BACKGROUND: Mammary neoplasms are common tumors in intact female dogs. Fine-needle aspiration cytology (FNAC) is a valuable diagnostic tool and has gained some credibility in the diagnosis of mammary tumors in dogs. Prompt classification of canine mammary tumors using cytology would enhance feasibility as a prognostic tool and guide clinical and surgical management. OBJECTIVES: We aimed to examine background elements to differentiate mammary tumors using FNAC. We proposed to distinguish simple from complex and mixed tumors by identifying myoepithelial (ME) cells and different types of extracellular matrix. Additionally, we determined the accuracy of FNAC to differentiate benign from malignant tumors. METHODS: One hundred and one mammary tumors from female dogs were included in this study. We compared FNAC using histopathology as the gold standard. Cellular and background components were evaluated and identified. The cytologic accuracy, sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (NPV) for diagnosing malignancy were determined, excluding inadequate samples. RESULTS: The cytologic-histologic agreement was 92.5% for simple carcinomas, 57.9% for complex-type carcinomas, 57.1% for mixed-type carcinomas, 27.3% for carcinosarcomas, and 100% for osteosarcomas. Myoepithelial cells were successfully identified using FNAC. Myxoid and chondroid/osteoid matrix were satisfactorily recognized. Cytologic accuracy, Se, Sp, PPV, and NPV for diagnosing malignancy were 99%, 100%, 83%, 99%, and 100%, respectively. CONCLUSIONS: Chondroid/osteoid matrix was noted in mixed tumors but not in complex tumors. Myxoid matrix, often associated with ME cells, was noted in complex and mixed tumors. Mesenchymal cells were differentiated from ME cells, allowing the distinction of simple carcinomas with scirrhous reaction from complex and mixed tumors.

Sinonasal neoplasms in 49 dogs: clinical, macroscopic, and histopathological aspects / Neoplasmas nasossinusais em 49 cães: aspectos clínicos, macroscópicos e histopatológicos

This study aimed to quantify nasosinusal neoplasms diagnosed in dogs in 20 years (2000-2019) and characterize the main clinical, macroscopic, and histological aspects of these neoplasms. The sex, breed, age, skull conformation, the main clinical signs, and the anatomopathological characteristics (distribution, macroscopy, and histology) were computed. During this period, 49 dogs were affected by neoplasms in these regions, totaling 50 neoplasms (one dog had two neoplasms of different locations and histogenetic origins). Similar amounts of mixed-breed dogs (25/49) and purebred dogs (24/49) were affected, these distributed in 16 breeds. Among purebreds, it was noted that dogs with mesocephalic cranial conformation (12/24) were the most affected, followed by dolichocephalic (10/24) and brachycephalic (2/24). There were 22 cases in males and 27 in females, making a proportion of 1:1.23. There was an age variation from 11 months to 16 years old. The epithelial neoplasms have occurred in older dogs compared to those of other histogenic origins (mesenchymal and other origins/round cells). The main clinical signs were similar between the histogenetic categories, related to the involvement of the upper respiratory tract, sometimes accompanied by nervous signs (when there was brain invasion of nasal neoplasms or vice versa). The possible origin site was mostly in the nasal cavity concerning the paranasal sinuses (and other locations). Invasions occurred in different tissues adjacent to the nasal cavity and paranasal sinuses, resulting in cranial and facial deformities (21/49). The frequency was 48% of epithelial neoplasms, 32% of mesenchymal neoplasms, and 10% of neoplasms with other origins and round cells. The neoplasms most frequently observed, in decreasing order of frequency, were: adenocarcinoma (9/50), squamous cell carcinoma (9/50), transmissible venereal tumor (5/50), osteosarcoma (5/50), chondrosarcoma (4/50), and undifferentiated sarcoma (4/50). Through this study, it was possible to establish the frequency of these neoplasms in 20 years and their clinical, macroscopic, and histological characteristics.(AU)

Este estudo teve como objetivo quantificar os neoplasmas nasossinusais diagnosticados em cães em 20 anos (2000-2019) e caracterizar os principais aspectos clínicos, macroscópicos e histológicos desses neoplasmas. Foram computados sexo, raça, idade, conformação do crânio, principais sinais clínicos e características anatomopatológicas (distribuição, macroscopia e histologia). Nesse período, 49 cães foram acometidos por neoplasmas nessas regiões, totalizando 50 neoplasmas (um cão tinha dois neoplasmas de localização e origens histogenéticas distintas). Foram acometidas quantidades semelhantes de cães sem raça definida (25/49) e de cães com raça definida (24/49), estes distribuídos em 16 raças. Entre os cães com raça definida, notou-se que os cães com conformação craniana mesocefálica (12/24) foram os mais acometidos, seguidos pelos dolicocefálicos (10/24) e braquicefálicos (2/24). Foram observados 22 casos em machos e 27 em fêmeas, perfazendo a relação de 1:1,23. Ocorreu uma variação de idade de 11 meses a 16 anos; tendo os neoplasmas epiteliais ocorrido em cães mais velhos quando comparado aos de outras origens histogênicas (mesenquimais e outras origens/células redondas). Os principais sinais clínicos foram semelhantes entre as categorias histogenéticas, sendo relacionados ao comprometimento do trato respiratório superior, por vezes acompanhados de sinais nervosos (quando houve invasão encefálica de neoplasmas nasais ou vice-versa). O possível local de origem em sua maioria foi na cavidade nasal em relação aos seios nasais (e de outras localizações). Ocorreram invasões para diferentes tecidos adjacentes à cavidade nasal e seios paranasais, tendo como consequência deformidades cranianas e faciais (21/49). A frequência foi de 48% de neoplasmas epiteliais, 32% de neoplasmas mesenquimais e 10% de neoplasmas com outras origens e de células redondas. Os neoplasmas mais frequentemente observados, em ordem decrescente de frequência, foram: adenocarcinoma (9/50), carcinoma de células escamosas (9/50), tumor venéreo transmissível (5/50), osteossarcoma (5/50), condrossarcoma (4/50) e sarcoma indiferenciado (4/50). Com isso, pode-se estabelecer a frequência desses neoplasmas em 20 anos, bem como suas características clínicas, macroscópicas e histológicas.(AU)

Testicular tumors in 190 dogs: clinical, macroscopic and histopathological aspects / Neoplasmas testiculares em 190 cães: aspectos clínicos, macroscópicos e histopatológicos

This study aimed to characterize the prevalence and clinical, macroscopic and histopathological aspects of dogs affected by testicular tumors based on biopsy specimens from the Laboratório de Patologia Veterinária of the Universidade Federal de Santa Maria (LPV-UFSM) over 19 years. Parameters regarding the age, size, and breed of the affected dogs were also established. Of all dogs with some type of neoplasm submitted to histopathological analysis at the LPV over these 19 years (n=1,900), 213 (11.2%) had at least one testicular neoplasm. The tissues of 190 dogs (with 220 neoplasms) were available for histological reassessment. The dogs in this study had different types of testicular tumors with relatively similar frequencies. In descending order, the most frequent testicular neoplasms were seminomas (88/220), Leydig (interstitial) cell tumor (LCT; 64/220), Sertoli cell tumor (SCT; 61/220), and mixed germ cell-sex cord stromal tumor (MGSCT) (07/220). Among the dogs of defined breed (119 cases), large breeds had the largest number of cases (50/119), followed by small (47/119) and medium-sized (22/119) breeds. The ages of dogs affected by testicular tumors ranged from 10 months to 18 years. Increased testicular volume was the most common clinical manifestation. Eleven dogs presented information about clinical signs suggestive of hyperestrogenism syndrome (feminization). In seminomas, the diffuse pattern predominated over the intratubular pattern. Two sites (luminal and basal compartments) suggestive of the onset of neoplastic transformations in germ cells were observed in intratubular seminomas. They corroborate the hypothesis that canine seminomas possibly have pathogenesis similar to that observed in human spermatocytic seminomas. The SCTs and LCTs presented high cell morphology variation. SCTs had neoplastic cells organized in five different histological arrangements. As for LCT, solid-diffuse and cystic-vascular histological patterns were the most commonly observed. Through this study, it was possible to establish some of the leading clinical, macroscopic, and histopathological aspects of testicular neoplasms diagnosed over 19 years in the area covered by the LPV-UFSM.(AU)

Este estudo teve por objetivo caracterizar a prevalência, aspectos clínicos, macroscópicos e histopatológicos dos cães acometidos por neoplasmas testiculares, a partir dos espécimes de biópsias do Laboratório de Patologia Veterinária da Universidade Federal de Santa Maria (LPV-UFSM) em 19 anos. Parâmetros quanto à idade, porte, raça dos cães acometidos também foram estabelecidos. De todos os cães com algum tipo de neoplasma submetido à análise histopatológica no LPV nesses 19 anos (n=1.900), 213 (11,2%) tinham ao menos um neoplasma testicular. Os tecidos de 190 cães (com 220 neoplasmas) estavam disponíveis para reavaliação histológica. Os cães deste estudo apresentaram diferentes tipos de neoplasmas testiculares com frequências relativamente semelhantes. Em ordem decrescente, os neoplasmas testiculares mais frequentes foram: seminomas (88/220), leydigomas (64/220), sertoliomas (61/220) e o tumor misto de células germinativas e do estroma do cordão sexual (MGSCT; 07/220). Dentre os cães com raça definida (119 casos), as raças de grande porte tiveram o maior número de casos (50/119), seguido das raças de pequeno (47/119) e médio porte (22/119). As idades dos cães acometidos por neoplasmas testiculares variaram de 10 meses a 18 anos. Aumento de volume testicular foi a manifestação clínica mais comum. Onze cães tinham informações sobre sinais clínicos sugestivos da síndrome da feminilização. Nos seminomas, houve o predomínio do padrão difuso sobre o intratubular. Dois locais (compartimentos luminal e basal) sugestivos de início das transformações neoplásicas nas células germinativas foram observados nos seminomas intratubulares, corroborando com a hipótese de que os seminomas caninos possivelmente tem patogênese semelhante à observada nos seminomas espermatocíticos humanos. Sertoliomas e leydigomas foram neoplasmas com alta variação na morfologia celular. Os sertoliomas tinham células neoplásicas dispostas em cinco arranjos histológicos distintos. Quanto aos leydigomas, os padrões histológicos sólido-difuso e cístico-vascular foram os mais comumente observados. Através deste estudo foi possível estabelecer alguns dos principais aspectos clínicos, macroscópicos e histopatológicos dos neoplasmas testiculares diagnosticados em 19 anos na área de abrangência do LPV-UFSM.(AU)

Psittacid herpesvirus 3 infection in rose-ringed parakeets in southern Brazil.

We diagnosed disease caused by psittacid herpesvirus 3 (PsHV-3), a novel psittacid pathogen, in rose-ringed parakeets (Psittacula krameri) housed in an exotic psittacine breeding colony in southern Brazil. The disease affected several adult birds. Clinical signs included apathy, tachypnea, and wheezing. Four birds were autopsied, and sections of lungs and liver were examined histologically and by electron microscopy (EM), revealing pulmonary congestion, bronchopneumonia, or multifocal necrosis of tertiary bronchi, with syncytial cells and eosinophilic intranuclear inclusion bodies. Viral particles morphologically compatible with herpesviruses were observed by EM in lung sections. PCR with pan-herpesvirus primers performed on total DNA extracted from paraffinized tissue resulted in a 278-bp product. Sequencing of the amplicon revealed 93% nucleotide identity with a PsHV-3 sequence available in GenBank. Phylogenetic analysis grouped the obtained sequence with the only PsHV-3 DNA polymerase gene sequence available (GenBank accession JX028240) and separated the sequence from psittacid herpesviruses 1 and 2. The clinical, pathologic, and molecular findings support the association of PsHV-3 with pneumonia found in these rose-ringed parakeets in southern Brazil.

Pythiosis in cattle in Northeastern Brazil / Pitiose em bovinos no Nordeste do Brasil

The epidemiological, clinical and pathological aspects of cutaneous pythiosis occurring in cattle from three farms in the Northeastern of Brazil are described. A biopsy of the lesions of one bovine from each farm was performed. In two cases, the affected cattle had contact with water accumulated in dams during the dry season in the semiarid region. Another case occurred in the coastal tropical region in cattle grazing around irrigation channels. Clinically, lesions were observed mainly on the skin of the thoracic and/or pelvic limbs, characterized by flat and irregular ulcerated areas or nodules of varying sizes, some with fistulous tracts penetrating deep into the subcutaneous tissue. In one case the regional lymph nodes were affected. Histologically, in all cases, pyogranulomatous dermatitis associated with negative hyphae images, in hematoxylin-eosin stained sections, were observed. In sections stained by Grocott methenamine silver, the hyphae measured 2-8μm and had irregular ramifications and rare septations. Immunohistochemistry technique demonstrated strong immunolabeling for Pythium insidiosum. Pythiosis should be included in the differential diagnosis of dermatopathies in cattle in the Northeastern of Brazil.(AU)

Descrevem-se os aspectos epidemiológicos, clínicos e patológicos da pitiose cutânea em bovinos de três propriedades do Nordeste do Brasil. Uma biópsia das lesões de um bovino de cada propriedade foi realizada. Em dois casos, os bovinos afetados tiveram acesso à água acumulada em açudes durante a estação seca da região semiárida. O outro bovino acometido estava a pastoreio próximo a canais de irrigação na região litorânea. Clinicamente, as lesões foram observadas principalmente na pele dos membros torácicos e/ou pélvicos e caracterizavam-se por áreas planas e irregulares de ulceração ou nódulos de tamanhos variados, alguns com trajetos fistulosos penetrando profundamente no tecido subcutâneo. Em um caso, os linfonodos regionais foram afetados. Histologicamente, em todos os casos, observou-se dermatite piogranulomatosa associada a imagens negativas de hifas, em secções corados por hematoxilina e eosina. Em seções coradas por metenamina de prata de Grocott, as hifas mediam 2-8μm e possuíam ramificações irregulares com raras septações. A imuno-histoquímica demonstrou forte imunomarcação para Pythium insidiosum. A pitiose deve ser incluída como diagnóstico diferencial de dermatopatias de bovinos no Nordeste do Brasil.(AU)

Use of different fixation times and application of two immunohistochemical methods for detection of KIT and Ki67 proteins in canine cutaneous mast cell tumors / Utilização de diferentes tempos de fixação e métodos imuno-histoquímicos na detecção das proteínas KIT e Ki67 em mastocitomas cutâneos caninos

Due to the high prevalence of mast cell tumors (MCTs) in the diagnostic routine, several factors, especially prognostic, have been sought to determine the biological behavior of these neoplasms. Immunohistochemistry (IHC) is one of the main tools utilized to biologically differentiate more aggressive tumors from less aggressive ones. However, some immunostainings are influenced by formalin fixation, interfering with the results. This is both a retrospective and prospective study of MCTs diagnosed in laboratory routine. A total of 25 samples, without knowledge about fixation time, were analyzed in the retrospective study, whereas 12 samples, with known fixation times, were assessed in the prospective study. Two histologic grading systems (Patnaik and Kiupel), special staining of toluidine blue, and IHC for KIT and Ki67 proteins were applied in both studies. Additionally, two amplification systems (biotinylated and non-biotinylated) for Ki67 protein and counting of the argyrophilic nucleolar organizing regions (AgNOR method) were tested in the prospective study. In the retrospective study, greater agreement between the evaluating pathologists was observed when the Kiupel system was used. IHC staining for KIT protein was effective in both studies, regardless of fixation time. IHC staining for Ki67 protein was highly sensitive to formaldehyde, and staining failure was observed in 56% of the cases in the retrospective study. In the prospective study, samples fixed for longer than 24 hours showed a reduction in the number of stained cells (altering the determination of the cell growth fraction) or showed absence of IHC staining in both amplification systems. The use of the AgNOR method to evaluate the rate of cell proliferation may be an alternative when the fixation time of the neoplasm is unknown or longer than 24 hours.(AU)

Devido a alta prevalência dos mastocitomas cutâneos caninos (MCCs) na rotina diagnóstica, vários fatores, especialmente fatores prognósticos, têm sido buscados para auxiliar na determinação do comportamento biológico desse neoplasma. A imuno-histoquímica é uma das principais ferramentas empregadas para diferenciar tumores biologicamente mais agressivos de tumores menos agressivos. Entretanto, algumas imunomarcações sofrem influência pela fixação em formol, interferindo nos resultados. Este estudo compreendeu avaliar através de uma etapa retrospectiva e uma etapa prospectiva casos de MCCs diagnosticados na rotina laboratorial. Um total de 25 amostras, sem conhecimento do tempo de fixação, foi analisado no estudo retrospectivo e 12 amostras, com tempos de fixação conhecidos, no estudo prospectivo. Foram aplicados nos dois estudos, dois sistemas de graduação histológica (Patnaik e Kiupel), a coloração especial de azul de toluidina e a imuno-histoquímica para as proteínas KIT e Ki67. Adicionalmente, no estudo prospectivo, foram testados dois sistemas de amplificação (biotinilado e não biotinilado) para a proteína Ki67 e a técnica de AgNOR (contagem das regiões organizadoras nucleolares argirofílicas). Na etapa retrospectiva, observou-se uma maior concordância entre os patologistas avaliadores quando o sistema Kiupel foi utilizado. A imunomarcação para KIT se manteve eficaz em ambos os estudos, independentemente do tempo de fixação. A imunomarcação para o Ki67 mostrou-se altamente sensível ao tempo de fixação em formol, sendo observada falha na imunomarcação em 56% dos casos do estudo retrospectivo. No estudo prospectivo, constatou-se que amostras fixadas por mais de 24 horas em formol apresentaram redução na quantidade de células imunomarcadas (alterando a determinação da fração de crescimento celular) ou apresentaram ausência de imunomarcação em ambos os sistemas de amplificação. A utilização do método AgNOR, para avaliar a taxa de proliferação celular, pode ser uma alternativa quando o tempo de fixação do neoplasma for desconhecido ou superior a 24 horas.(AU)

Efficacy of Azithromycin and Miltefosine in Experimental Systemic Pythiosis in Immunosuppressed Mice.

We evaluated the efficacy of azithromycin (50 mg/kg, every 12 h [q12h] orally) and miltefosine (25 mg/kg, q24h orally) treatments in an experimental model of vascular/disseminated pythiosis in immunosuppressed mice. Azithromycin was the only treatment able to reduce mortality. The histopathological findings showed acute vascular inflammation, pathogen dissemination, necrotizing myositis, neuritis, and arteritis. The results suggest that azithromycin, but not miltefosine, may have clinical relevance in the treatment of vascular/disseminated pythiosis.

Identification and phylogenetic analysis of clade C Avipoxvirus in a fowlpox outbreak in exotic psittacines in southern Brazil.

Fowlpox is one of the oldest diseases reported in birds. The causative genus Avipoxvirus affects ~232 domestic and wild species. We present herein the history, clinical findings, and macroscopic and histologic lesions caused by a clade C poxvirus in an exotic psittacine breeding colony in southern Brazil. Clinical signs included yellow nodular lesions at the commissure of the beak and on the periocular skin, loss of appetite, and death. Fifty birds were autopsied, and fragments of periocular skin, tongue, and trachea were examined histologically, which revealed hyperkeratosis associated with eosinophilic intracytoplasmic inclusion bodies. Tracheal fragments and periocular skin were subjected to nested PCR and phylogenetic analyses. The sequenced strain showed 99.58% identity with the nucleotide sequences of Avipoxvirus strains AY53011, KC018069, AM050383, and AM05382 isolated from birds in Germany, United States, and United Kingdom. The strain was grouped under clade C, which represents isolates exclusively from the Psittacidae family. The infection caused by clade C Avipoxvirus in the exotic psittacines examined ( Platycercus sp. and Psephotus haematonotus) demonstrates the circulation of this clade in this breeding colony.

An experimental murine model of otitis and dermatitis caused by Malassezia pachydermatis.

We report a malasseziosis model in immunocompromised Swiss mice. For this model, the mice were immunosuppressed with a combination of cyclophosphamide at 150 mg/kg and hydrocortisone acetate at 250 mg/kg. Two groups were formed according to the site of inoculation. Dermatitis group received an intradermal injection of 5 × 106 cell/mouse at a shaved dorsal region, while the otitis group received the same inoculum in the middle ear. Five animals/group were euthanised at different times, and the skin and ear were histopathologically analysed. During the first euthanasia, which occurred after inoculation, microscopic examination showed that all mice presented budding yeast-like in a tissue sample. The presence of yeasts decreased over time being undetected on the 17th day (dermatitis group) and the 21st day (otitis group) after inoculation. This is the first murine model for malasseziosis that can be useful for evaluating new treatment approaches.

Mielodisplasia na peritonite infecciosa felina: 16 casos (2000-2017) / Myelodysplasia in feline infectious peritonitis: 16 cases (2000-2017)

Apesar da prevalência da peritonite infecciosa felina (PIF) ser alta em praticamente o mundo todo, estudos anatomopatológicos recentes acerca dessa doença são escassos. Não obstante, as características microscópicas da medula óssea de gatos com PIF estão ausentes da literatura consultada. O objetivo deste artigo é descrever alterações medulares ósseas vistas em casos espontâneos de PIF. As medulas ósseas colhidas sistematicamente da região diafisária dos fêmures de 16 gatos necropsiados no Laboratório de Patologia Veterinária (LPV) da Universidade Federal de Santa Maria (UFSM), Rio Grande do Sul, entre janeiro de 2000 e junho de 2017, e que tiveram diagnóstico definitivo de PIF, foram avaliadas fenotípica (histopatologia - hematoxilina e eosina e histoquímica - reação de Perls) e imunofenotipicamente (utilizando marcadores mieloides (anti-MAC387) e de linfócitos (anti-CD79αcy e anti-CD3). Os resultados permitem afirmar que, independentemente da apresentação clinicopatológica da doença ocorrem as seguintes alterações: 1) hiperplasia mieloide; 2) hipoplasia eritroide, 3) displasia megacariocítica (dismegacariocitopoiese) e 4) plasmocitose medular. Exclusivamente nos casos de PIF seca há hemossiderose medular óssea e hepática. Essas alterações permitem estabelecer que gatos com PIF desenvolvem mielodisplasia, uma lesão mieloproliferativa muito semelhante àquela relatada em humanos infectados pelo HIV. Sugere-se que a partir dos achados aqui descritos, a mielodisplasia seja considerada a principal responsável pelas alterações hematológicas observadas na PIF, especialmente pela anemia e trombocitopenia arregenerativas frequentemente desenvolvidas pelos pacientes com essa doença.(AU)

Although the prevalence of feline infectious peritonitis (FIP) is high worldwide, recent anatomopathological studies about this disease are scarce. Information on the microscopic characteristics of the bone marrow in FIP-affected cats are absent in the available literature. Based on this, the purpose of this article is to describe bone marrow lesions seen in spontaneous cases of FIP. The bone marrow collected systematically from the femoral diaphysis of 16 cats necropsied in the Laboratory of Veterinary Pathology (LPV) of the Federal University (UFSM) of Southern Brazil, between January 2000 and June 2017, with a definitive diagnosis of FIP, were evaluated phenotypically (histopathology - hematoxylin and eosin and histochemistry - Perls stain) and immunophenotypically (immunohistochemistry using myeloid - Anti-MAC387, and lymphocytic - Anti-CD79 αcy and Anti-CD3 markers). Regardless the following was observed the clinicopathological form of the disease ("dry" - noneffusive or "wet" - effusive): 1) myeloid hyperplasia; 2) erythroid hipoplasia; 3) megakaryocytic dysplasia (dismegakaryocytopoiesis); and 4) medullary plasmacytosis. Exclusively in cases of "dry FIP" was bone marrow and hepatic hemosiderosis. These lesions allowed establishing that cats with FIP develop myelodysplasia, a myeloproliferative lesion very similar to that reported in HIV-infected humans. It is suggested that, based on the findings described here, myelodysplasia is considered to be the main cause of hematological abnormalities observed in FIP, especially for non-regenerative anemia and thrombocytopenia, frequently developed by patients.(AU)

Caracterização do gênero, da raça e da idade de uma população de 7. 780 cães da Região Central do Rio Grande do Sul submetidos à necropsia ao longo de cinco décadas (1964-2013) / Characterization of gender, breed and age in a population of 7. 780 dogs submitted for necropsy over five decades (1964-2013) in central Rio Grande do Sul, Brazil

Devido à ausência de um banco de dados demográficos da população canina que habita a Região Central do Rio Grande do Sul (RS) e à necessidade em se estabelecer uma "população controle" para a melhor interpretação da prevalência das doenças diagnosticadas pelo Laboratório de Patologia Veterinária (LPV-UFSM) da Universidade Federal de Santa Maria (UFSM), este estudo objetivou realizar uma análise das características relacionadas à raça, ao gênero e à idade dos cães necropsiados neste serviço de diagnóstico ao longo de 50 anos (1964-2013). Para isto, os laudos de necropsias de cães, realizadas entre 1964 e 2013, foram revisados, e deles foram retiradas informações referentes ao gênero, à idade e às raças de todos os cães oriundos dos municípios que compõem a Região Central do RS. Ao todo, 7.780 cães foram necropsiados; desses, 469 (6%) na primeira década (1964-1973), 1.133 (14,6%) na segunda década (1974-1983), 1.334 (17,1%) na terceira década (1984-1993), 1.705 (22%) na quarta década (1994-2003) e 3.139 (40,3%) na quinta década (2004-2013). Do total de cães com gênero informado nos laudos, 52,6% eram machos e 47,4% eram fêmeas. A mediana da idade de morte foi de três anos. Dos cães cuja raça foi informada nos laudos, 59,8% eram de raça definida (RD) e 40,2% não tinham raça definida (SRD). As raças de porte grande ou gigante mais frequentes foram: Pastor Alemão (17,2%), Boxer (6,9%), Rottweiler (5,3%), Fila Brasileiro (4,6%), Pointer Inglês (3,9%), Collie Pelo Longo (3,7%) Dobermann (3,7%) e Labrador Retriever (2,1%). As raças de porte pequeno ou médio mais frequentes foram: Poodle (8,9%), Dachshund (6,3%), Pinscher Miniatura (5,6%), Cocker Spaniel Inglês (4,5%), Pequinês (3,4%), Yorkshire Terrier (3,3%) e Terrier Brasileiro (2,8%). Houve um aumento na proporção de fêmeas e um crescimento na mediana referente à idade de morte ao longo das cinco décadas avaliadas. Apesar de não ter havido um aumento relevante na proporção de cães de RD em comparação com os SRD, observaram-se algumas mudanças na ocorrência de diferentes raças ao longo do tempo, incluindo principalmente uma dramática diminuição na percentagem de Pequinês, Terrier Brasileiro, Pointer Inglês e Pastor Alemão, e um aumento marcado na percentagem de Poodle, Dachshund, Rottweiler e Labrador Retriever. Os resultados aqui apresentados servirão como um subsídio comparativo para futuros estudos retrospectivos sobre prevalência de doenças em cães da Região Central do RS, auxiliando para uma mais correta compreensão e interpretação dos resultados encontrados nesses levantamentos de dados.(AU)

Based on the lack of demographic database on the canine population living in the midland region of Rio Grande do Sul State, Brazil, and on the need for a "control population" in the accomplishment of several prevalence-based studies of different diseases diagnosed at the Laboratório de Patologia Veterinária (LPV) of the Universidade Federal de Santa Maria (UFSM), the objective of this study was to describe the breed, gender and age characteristics of the population of dogs necropsied in this diagnostic service over 50 years (1964-2013). The protocols of necropsies performed on dogs and recorded in the LPV-UFSM between 1964 and 2013 were reviewed, and information related to gender, age and breed from dogs from all the districts within the Central Region of RS were separated. A total of 7,780 dogs were necropsied, among which 469 (6%) were registered in the first decade (1964-1973), 1,133 (14.6%) in the second decade (1974-1983), 1,334 (17.1%) in the third decade (1984-1993), 1,705 (22%) in the fourth decade (1994-2003) and 3,139 (40.3%) in the fifth decade (2004-2013). Of dogs whose gender was reported in the protocols, 52.6% were males and 47.4% were females. The median age of death was 3 years. Of dogs whose breed was reported in the protocols, 59.8% were purebred and 40.2% were mixed breed. The most common large and giant breed dogs were German Shepherd Dog (17.2%), Boxer (6.9%), Rottweiler (5.3%), Fila Brasileiro (4.6%), English Pointer (3.9%), Collie Rough (3.7%), Dobermann (3.7%), and Labrador Retriever (2.1%). The most common small and medium breed dogs were Poodle (8.9%), Dachshund (6.3%), Miniature Pinscher (5.6%), English Cocker Spaniel (4.5%), Pekingese (3.4%), Yorkshire Terrier (3.3%), and Brazilian Terrier (2.8%). The percentage of females and the median age of death showed an increase during the five decades of this study. Although there has been a significant increase in the proportion of pure breed dogs compared to mongrels, we observed some changes in the occurrence of different breeds over time, including a significant decrease in the frequency of the Pekingese, Brazilian Terrier, English Pointer, and German Shepherd Dog, and significant increase in the frequency of the Poodle, Dachshund, and Labrador Retriever. The results presented here will serve as an allowance for future comparative studies of disease prevalence in dogs of Central Region of RS, helping to a more correct understanding and interpretation of results from these data surveys.(AU)