Gross, histologic, and ultrastructural features of iridophoromas in Siamese fighting fish (Betta splendens).

Pigment-containing and light-reflecting cell neoplasms, generically termed chromatophoromas, affect fish, reptiles, and amphibians. Chromatophoromas of light-reflecting cells are named iridophoromas. In this study, we aimed to describe the gross, histologic, and ultrastructural findings of 71 cases of iridophoromas in farmed Siamese fighting fish (Betta splendens). Macroscopically, iridophoromas appeared as whitish, gray, or black friable masses or plaques in the fin, trunk/tail, or head of the fish. Forty-five tumors (63%) were malignant and invaded the adjacent skeletal muscle and/or metastasized to other organs, whereas 26 (37%) tumors were restricted only to the skin, but due to the cytologic similarity to the malignant counterpart, we were not able to classify them as malignant or benign. Sixty-five (91%) tumors were classified as iridophoromas, whereas 6 (8%) were diagnosed as mixed chromatophoromas. Despite immunolabeling for PNL-2, melan A, or S-100 failing to demonstrate antigen expression, ultrastructural analysis identified light-reflecting neoplastic cells, unequivocally confirming iridophoromas as the predominant tumor. The high incidence of iridophoromas in Siamese fighting fish from the same breeding facility, coupled with a higher occurrence in royal blue and fancy copper color patterns and in young males, suggests a potential genetic/hereditary factor in the tumorigenesis of these neoplasms.

A mystery revealed: an update on eosinophil and other blood cell morphology of the Argentine black and white tegu (Salvator merianae).

Reptile white blood cell (WBC) morphological features are strikingly variable across species. In the Argentine black and white tegu (Salvator merianae), red tegu (Salvator rufescens), and Savannah monitor (Varanus exanthematicus), previous reports described a WBC type with a single distinct, clear, linear- to ovoid- to crescent-shaped inclusion of presumptive monocytic origin. The objective of this study was to further investigate the origin of this unique WBC type with crescent-shaped inclusions. Blood samples from two Argentine black and white tegus, tegu 1, a 4-year-old female, and tegu 2, a 2-year-old presumed male, were submitted for routine hematological evaluation. Additional blood films were prepared and stained with these cytochemical stains: alkaline phosphatase (ALP; naphthol AS-MX phosphate substrate), alpha-naphthyl butyrate esterase, alpha-chloroacetate esterase, myeloperoxidase, Periodic acid-Schiff, and Sudan black B. Blood films from tegu 1 were also stained with a second ALP stain (5-bromo-4-chloro-3-indoxyl-phosphate and nitroblue tetrazolium substrate), Luna, luxol fast blue, and toluidine blue. The blood from tegu 1 was cytocentrifuged to isolate and fix the buffy coat in glutaraldehyde 2.5% aqueous solution for transmission electron microscopy. Six morphologically distinct WBC types were identified from tegu 1, including heterophils, basophils, monocytes, azurophils, lymphocytes, and the unique WBC type, which were identified as eosinophils with inclusions. WBC types in tegu 2 were similar; however, eosinophils lacked a discernable inclusion. Proper WBC identification will be useful in obtaining accurate hemogram data for this species.

Fatal Africanized bee attack in captive non-human primates (Saimiri ustus and Sapajus libidinosus).

Bee stings (BS) are a life-threatening issue and a growing concern for public health and animals in the Americas. We describe the clinical, pathological, and ultrastructural findings of a massive lethal bee attack in two non-human primates (NHPs). Both animals showed BS scattered throughout the skin, surrounded by a local reaction, diffuse pulmonary congestion, edema, hemorrhage, and remarkable degeneration and necrosis of renal epithelial cells from the proximal and distal tubules, characterizing a systemic bee envenomation reaction.

Poisoning by Baccharis coridifolia in Early-Weaned Beef Calves: Pathological Study and New Macrocyclic Trichothecene Identification.

This study investigated two outbreaks of spontaneous poisoning by Baccharis coridifolia (Asteraceae) in early-weaned beef calves in Tacuarembó, Uruguay. A total of 34 affected calves showed signs of salivation, anorexia, apathy, marked dehydration, and diarrhea. Deaths occurred 36-72 h after consumption and mortality varied from 37.5% to 43.3% for outbreak 1 and outbreak 2, respectively. The main pathological findings include diffuse severe necrosis of the prestomachs and lymphoid tissues. Ultrastructurally, epithelial cells of the rumen showed swelling, lysis of the organelles, degradation of intercellular attachments, and degradation of the nuclear chromatin. Using LC-MS with diagnostic fragmentation filtering, 56 macrocyclic trichothecenes including glycosyl and malonyl conjugates were identified. The total concentration of macrocyclic trichothecenes, including conjugates, was estimated to be 1.2 ± 0.1 mg/g plant material. This is the first report of these malonyl-glucose conjugates from Baccharis coridifolia.

Two Decades of Wildlife Pathogen Surveillance: Case Study of Choclo orthohantavirus and Its Wild Reservoir Oligoryzomys costaricensis.

The Costa Rican pygmy rice rat (Oligoryzomys costaricensis) is the primary reservoir of Choclo orthohantavirus (CHOV), the causal agent of hantavirus disease, pulmonary syndrome, and fever in humans in Panama. Since the emergence of CHOV in early 2000, we have systematically sampled and archived rodents from >150 sites across Panama to establish a baseline understanding of the host and virus, producing a permanent archive of holistic specimens that we are now probing in greater detail. We summarize these collections and explore preliminary habitat/virus associations to guide future wildlife surveillance and public health efforts related to CHOV and other zoonotic pathogens. Host sequences of the mitochondrial cytochrome b gene form a single monophyletic clade in Panama, despite wide distribution across Panama. Seropositive samples were concentrated in the central region of western Panama, consistent with the ecology of this agricultural commensal and the higher incidence of CHOV in humans in that region. Hantavirus seroprevalence in the pygmy rice rat was >15% overall, with the highest prevalence in agricultural areas (21%) and the lowest prevalence in shrublands (11%). Host-pathogen distribution, transmission dynamics, genomic evolution, and habitat affinities can be derived from the preserved samples, which include frozen tissues, and now provide a foundation for expanded investigations of orthohantaviruses in Panama.

Hantavirus in Panama: Twenty Years of Epidemiological Surveillance Experience.

Twenty years have passed since the emergence of hantavirus zoonosis in Panama at the beginning of this millennium. We provide an overview of epidemiological surveillance of hantavirus disease (hantavirus pulmonary syndrome and hantavirus fever) during the period 1999-2019 by including all reported and confirmed cases according to the case definition established by the health authority. Our findings reveal that hantavirus disease is a low-frequency disease, affecting primarily young people, with a relatively low case-fatality rate compared to other hantaviruses in the Americas (e.g., ANDV and SNV). It presents an annual variation with peaks every 4-5 years and an interannual variation influenced by agricultural activities. Hantavirus disease is endemic in about 27% of Panama, which corresponds to agroecological conditions that favor the population dynamics of the rodent host, Oligoryzomys costaricensis and the virus (Choclo orthohantavirus) responsible for hantavirus disease. However, this does not rule out the existence of other endemic areas to be characterized. Undoubtedly, decentralization of the laboratory test and dissemination of evidence-based surveillance guidelines and regulations have standardized and improved diagnosis, notification at the level of the primary care system, and management in intensive care units nationwide.

Pathologic and Immunohistochemical Evidence of Possible Francisellaceae among Aborted Ovine Fetuses, Uruguay.

The only genus of the Francisellaceae family known to contain species pathogenic to mammals is Francisella, for which reported cases in the Southern Hemisphere have been limited to Australia. We describe severe necrotizing and inflammatory lesions and intralesional immunohistochemical identification of Francisella sp. lipopolysaccharide among aborted ovine fetuses in Uruguay.

Motor and somatosensory degenerative myelopathy responsive to pantothenic acid in piglets.

This report describes 2 events of degenerative myelopathy in 4- to 27-day-old piglets, with mortality rates reaching 40%. Sows were fed rations containing low levels of pantothenic acid. Piglets presented with severe depression, weakness, ataxia, and paresis, which were more pronounced in the pelvic limbs. No significant gross lesions were observed. Histologically, there were degeneration and necrosis of neurons in the spinal cord, primarily in the thoracic nucleus in the thoracic and lumbar segments, and motor neurons in nucleus IX of the ventral horn in the cervical and lumbar intumescence. Minimal-to-moderate axonal and myelin degeneration was observed in the dorsal funiculus of the spinal cord and in the dorsal and ventral nerve roots. Immunohistochemistry demonstrated depletion of acetylcholine neurotransmitters in motor neurons and accumulation of neurofilaments in the perikaryon of neurons in the thoracic nucleus and motor neurons. Ultrastructurally, the thoracic nucleus neurons and motor neurons showed dissolution of Nissl granulation. The topographical distribution of the lesions indicates damage to the second-order neurons of the spinocerebellar tract, first-order axon cuneocerebellar tract, and dorsal column-medial lemniscus pathway as the cause of the conscious and unconscious proprioceptive deficit, and damage to the alpha motor neuron as the cause of the motor deficit. Clinical signs reversed and no new cases occurred after pantothenic acid levels were corrected in the ration, and piglets received parenteral administration of pantothenic acid. This study highlights the important and practical use of detailed neuropathological analysis to refine differential diagnosis.

Malignant epithelioid mesothelioma in senile Red Sindhi cows from Brazil / Mesotelioma epitelial maligno em vacas senis Sindi do Brasil

ABSTRACT: Mesotheliomas in cattle are often described as isolated case reports, and investigations of multiple cases within the same bovine herd are lacking. A series of cases of malignant epithelial mesothelioma, tubulopapilary type, is described in five 15 to 21-year-old Red Sindhi cows from the same herd. Clinical signs included three to eight months of progressive emaciation, dehydration, subcutaneous edema of the lower extremities, and abdominal distension. Grossly, severe subcutaneous edema and hydroperitoneum were noted. Multiple organs' parietal and visceral serosal surfaces had multifocal to coalescing yellow, firm, sessile nodules ranging from 0.1 to 29.0cm. Similar free nodules floated in the peritoneal fluid. Histologically, the masses comprised a layer of cubic to columnar neoplastic cells forming papillary or cystic proliferation supported by a dense fibrovascular stroma. Neoplastic cells had strong and diffuse cytoplasmic immunolabeling for pan-cytokeratin but were negative for cytokeratin 7 and vimentin. Ultrastructurally, neoplastic cells had delicate microvilli and tight and anchoring junctions. Within the cytoplasm, a moderate amount of loose aggregate of intermediary filament with small mitochondria was observed. Epidemiological investigation evidenced endogamy in this herd. Asbestos exposure was not detected. The diagnosis was based on clinical, gross, histological, and immunohistochemical findings and confirmed by transmission electron microscopy features. A definitive underlying etiology remains unknown.

RESUMO: Mesotelioma em bovinos são frequentemente relatados como casos isolados, descrições de múltiplos casos no mesmo rebanho bovino não foram encontrados. Descreve-se uma série de casos de mesotelioma epitelial maligno, tipo tubulopapilar, em cinco vacas Red Sindi de 15 a 21 anos de idade do mesmo rebanho. Os sinais clínicos incluíram emagrecimento progressivo, desidratação, edema subcutâneo das extremidades dos membros e distensão abdominal em um curso clínico que variou de três a oito meses. Macroscopicamente, observou-se edema subcutâneo acentuado e hidroperitônio. Nas serosas parietais e viscerais de múltiplos órgãos haviam nódulos multifocais a coalescentes amarelo-claros, firmes e sésseis que variavam de 0,1 a 29,0 centímetros de diâmetro. Nódulos livres semelhantes também flutuavam no líquido peritoneal. Histologicamente, as massas eram compostas por uma camada de células cúbicas a colunares formando proliferação papilar ou cística sustentada por estroma fibrovascular denso. As células neoplásicas apresentavam imunomarcação citoplasmática forte e difusa para pan-citoqueratina, mas eram negativas para citoqueratina 7 e vimentina. Ultraestruturalmente, as células neoplásicas apresentavam delicadas microvilosidades e junções comunicantes e de ancoragem. No citoplasma observou-se moderada quantidade de agregados de filamentos intermediários soltos e pequenas mitocôndrias. A investigação epidemiológica revelou que não houve inserção de bovinos de outros rebanhos por mais de 30 anos e evidenciou endogamia. Não foram encontradas possíveis fontes de amianto para os bovinos deste rebanho. O diagnóstico de mesotelioma foi baseado em características clínicas, macroscópicas, histológicas, imuno-histoquímicas e confirmado pelos achados de microscopia eletrônica. A etiologia permanece desconhecida.

Intoxication of llamas by Astragalus punae in Argentina.

Several plants that contain indolizidine alkaloids, including swainsonine, are toxic to livestock, causing dysfunctional lysosomes and storage disease. Swainsonine induces a neurovisceral disease, known as locoism, in sheep, goats, and cattle, which occurs in several parts of the world, including, but not limited to, the western United States, China, and parts of Australia. In South America, locoism has been described in the Andean region of Argentina affecting sheep, cattle, and llamas. Intoxication by consumption of Astragalus punae was suspected in 4 llamas in Jujuy Province, northwestern Argentina. The grazing area contained abundant specimens of A. punae. The clinical course was ~15 d, and included moderate ataxia, incoordination of hindlimbs, and progressive loss of body condition. Microscopically, fine cytoplasmic microvacuolation was observed in the proximal convoluted renal tubules. Ultrastructurally, these changes consisted of severely dilated lysosomes. Swainsonine was detected in stem and leaf samples of A. punae at a concentration of 0.06%. Based on clinical history and signs, histologic and ultrastructural changes, and plant analysis, a diagnosis of swainsonine toxicosis caused by consumption of A. punae was made, which has not been reported previously, to our knowledge.

Endemic Xanthium strumarium poisoning in cattle in flooded areas of the Araguari River, Minas Gerais, Brazil.

In this paper, we describe poisoning outbreaks of Xanthium strumarium in cattle on the borders of the Araguari River, Southeastern Brazil. In this region, several hydroelectric plants promote transient flooding, which creates a favorable environment for the invasion of X. strumarium in extensive areas, often as the predominant species in those areas. The outbreaks occurred between July and September (dry season). Bovines of all ages were affected, including suckling animals. Mortality varied from 2% to 5.5%. The animals exhibited ataxia, weakness, loss of balance, recumbency, and the majority were found dead. Laboratory results showed a marked increase in the serum activities of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyltransferase. Histological and ultrastructural changes in the liver consisted of centrilobular necrosis and hemorrhage. On toxicological evaluation, the dicotyledons contained 0.30 µg/mg of atractyloside and 0.37 µg/mg of carboxyatractyloside. Considerable economic loss has occurred in this region due to the lack of knowledge regarding X. strumarium as a toxic plant and its adaptation to the environmental and climatic conditions of the region, which have made the condition endemic.

Survival of Lawsonia intracellularis in porcine peripheral blood monocyte-derived macrophages.

Lawsonia intracellularis, an obligately intracellular enteric bacterium, infects intestinal epithelial cells, but may also be found within macrophages in the intestinal lamina propria of affected pigs. Macrophages play an important role in host defense against infectious agents, but the role of this cell in L. intracellularis infection is not well understood. The aim of this study was to evaluate the permissibility of macrophages to L. intracellularis infection in vitro. Pure culture of L. intracellularis was added to swine peripheral blood monocyte-derived macrophages. Viability of intracytoplasmic L. intracellularis was evaluated at different time points by transmission electron microscopy (TEM). Potential replication of L. intracellularis in macrophages was also evaluated by qPCR. By TEM, phagocytosis L. intracellularis within of phagolysosomes were observed 1-hour post-infection (hpi) and bacterial structures in binary fission at 48 hpi. The number of intracellular bacteria was determined at 1, 4, 24, 48, and 72 hpi by qPCR in infected macrophages and compared to the number of intracellular bacteria from culture in McCoy cells. In both cell lines, the amount of L. intracellularis was decreased at 4 hpiand increased at 24 hpi. The number of intracellular bacteria continued to increase in McCoy cells over time. This is the first study showing interaction, survival and propagation of L. intracellularis in macrophages. These findings are critical to establish an experimental model for future studies of the pathogenesis of porcine proliferative enteropathy and the potential persistence of L. intracellularis in macrophages during chronic infections.

Tremorgenic syndrome caused by Ipomoea pes caprae in cattle / Síndrome tremorgênica causada pela ingestão de Ipomoea pes caprae em bovinos

Poisonous plants are a significant cause of death among adult cattle in Brazil. Plants that affect the central nervous system are widely spread throughout the Brazilian territory and comprise over 30 toxic species, including the genus Ipomoea, commonly associated with a lysosomal storage disease and a tremorgenic syndrome in livestock. We describe natural and experimental Ipomoea pes caprae poisoning in cattle from a herd in the Northside of Rio de Janeiro, Brazil. Affected cattle presented episodes of severe ataxia, abnormal posture followed by falling, muscular tremor, contraction, and spasticity, more prominent in the limbs, intensified by movement and forthcoming, and recumbence. Grossly, a substantial amount of leaves and petioles were found in the rumen. Histopathological examination showed degenerative neuronal changes, mostly in cerebellar Purkinje cells, which were confirmed with Bielschowsky silver. The characteristic clinical changes and mild histological lesion strongly suggested a tremorgenic syndrome. Lectin- immunohistochemistry evaluation reinforced this hypothesis; all lectins tested failed to react with affect neurons and Purkinje cells, which ruled out an underlying lysosomal storage disease. One calf given I. pes caprae leaves experimentally developed clinical signs similar to natural cases. On the 28th day of the experiment, the plant administration was suspended, and the calf recovered within four days. I. pes caprae's spontaneous tremorgenic syndrome in cattle is conditioned to exclusive feeding for several months. We were able to experimentally reproduce toxic clinical signs 12 days following the ingestion.(AU)

A intoxicação por plantas tóxicas está entre as três causas de morte mais importantes em bovinos adultos no Brasil. O grupo das plantas que causam alterações neurológicas, muito bem representada no país, encerra mais de trinta espécies tóxicas, entre as quais do gênero Ipomoea, amplamente distribuídas no território brasileiro. As plantas tóxicas desse gênero podem causar doenças do armazenamento ou síndrome tremorgênica. Descrevem-se a intoxicação natural e reprodução experimental por Ipomoea pes caprae em bovinos, verificada no norte do Estado do Rio de Janeiro. Foram observados episódios de intensa ataxia locomotora, postura anormal seguida de queda, incapacidade de levantar-se, tremores, contrações, espasticidades musculares nos membros, intensificados após estimulação ou a simples aproximação e decúbito. Nos bovinos afetados há mais de 6 meses, os sinais clínicos tornavam-se permanentes. À necropsia havia apenas significativa quantidade de folhas e pecíolos da planta no rúmen. O estudo histopatológico evidenciou lesões neuronais degenerativas principalmente nos neurônios de Purkinje. A impregnação argêntica pela técnica de Bielschowsky ratificou esses achados microscópicos. As lesões histológicas sutis associadas ao quadro clínico indicam que trata-se de intoxicação tremorgênica. O fato de não haver nenhum armazenamento intracitoplasmático, confirmado pelo resultado do estudo lectino-histoquímico (não houve afinidade das lectinas Con-A, WGA e sWGA e de outras lectinas empregadas aos neurônios de Purkinje e outros neurônios afetados), é suficiente para descartar a possibilidade de tratar-se de doença do armazenamento. No bezerro intoxicado experimentalmente verificaram-se sinais clínicos semelhantes, entretanto, com a interrupção do fornecimento da planta no 28º dia, os sinais clínicos desapareceram após quatro dias. I. pes caprae causa síndrome tremorgênica espontânea em bovinos, quando ingerida como alimentação exclusiva durante períodos prolongados (muitos meses). Experimentalmente, os primeiros sinais clínicos da intoxicação foram reproduzidos após 12 dias de ingestão da planta.(AU)

Tremorgenic syndrome caused by Ipomoea pes caprae in cattle / Síndrome tremorgênica causada pela ingestão de Ipomoea pes caprae em bovinos

Poisonous plants are a significant cause of death among adult cattle in Brazil. Plants that affect the central nervous system are widely spread throughout the Brazilian territory and comprise over 30 toxic species, including the genus Ipomoea, commonly associated with a lysosomal storage disease and a tremorgenic syndrome in livestock. We describe natural and experimental Ipomoea pes caprae poisoning in cattle from a herd in the Northside of Rio de Janeiro, Brazil. Affected cattle presented episodes of severe ataxia, abnormal posture followed by falling, muscular tremor, contraction, and spasticity, more prominent in the limbs, intensified by movement and forthcoming, and recumbence. Grossly, a substantial amount of leaves and petioles were found in the rumen. Histopathological examination showed degenerative neuronal changes, mostly in cerebellar Purkinje cells, which were confirmed with Bielschowsky silver. The characteristic clinical changes and mild histological lesion strongly suggested a tremorgenic syndrome. Lectin- immunohistochemistry evaluation reinforced this hypothesis; all lectins tested failed to react with affect neurons and Purkinje cells, which ruled out an underlying lysosomal storage disease. One calf given I. pes caprae leaves experimentally developed clinical signs similar to natural cases. On the 28th day of the experiment, the plant administration was suspended, and the calf recovered within four days. I. pes caprae's spontaneous tremorgenic syndrome in cattle is conditioned to exclusive feeding for several months. We were able to experimentally reproduce toxic clinical signs 12 days following the ingestion.(AU)

A intoxicação por plantas tóxicas está entre as três causas de morte mais importantes em bovinos adultos no Brasil. O grupo das plantas que causam alterações neurológicas, muito bem representada no país, encerra mais de trinta espécies tóxicas, entre as quais do gênero Ipomoea, amplamente distribuídas no território brasileiro. As plantas tóxicas desse gênero podem causar doenças do armazenamento ou síndrome tremorgênica. Descrevem-se a intoxicação natural e reprodução experimental por Ipomoea pes caprae em bovinos, verificada no norte do Estado do Rio de Janeiro. Foram observados episódios de intensa ataxia locomotora, postura anormal seguida de queda, incapacidade de levantar-se, tremores, contrações, espasticidades musculares nos membros, intensificados após estimulação ou a simples aproximação e decúbito. Nos bovinos afetados há mais de 6 meses, os sinais clínicos tornavam-se permanentes. À necropsia havia apenas significativa quantidade de folhas e pecíolos da planta no rúmen. O estudo histopatológico evidenciou lesões neuronais degenerativas principalmente nos neurônios de Purkinje. A impregnação argêntica pela técnica de Bielschowsky ratificou esses achados microscópicos. As lesões histológicas sutis associadas ao quadro clínico indicam que trata-se de intoxicação tremorgênica. O fato de não haver nenhum armazenamento intracitoplasmático, confirmado pelo resultado do estudo lectino-histoquímico (não houve afinidade das lectinas Con-A, WGA e sWGA e de outras lectinas empregadas aos neurônios de Purkinje e outros neurônios afetados), é suficiente para descartar a possibilidade de tratar-se de doença do armazenamento. No bezerro intoxicado experimentalmente verificaram-se sinais clínicos semelhantes, entretanto, com a interrupção do fornecimento da planta no 28º dia, os sinais clínicos desapareceram após quatro dias. I. pes caprae causa síndrome tremorgênica espontânea em bovinos, quando ingerida como alimentação exclusiva durante períodos prolongados (muitos meses). Experimentalmente, os primeiros sinais clínicos da intoxicação foram reproduzidos após 12 dias de ingestão da planta.(AU)

Fatal lancehead pit viper (Bothrops spp.) envenomation in horses.

Snake bite envenomations in farm animals are generally overestimated as the cause of mortality in rural areas in Latin America. However, most cases are based only on anecdotal information and assumptions, and lack diagnostic evidence. There are few proven reports of envenomation and death in horses caused by snakebites from members of the Bothrops genus (lancehead pit vipers). This study presents epidemiological and clinical-pathological findings of fatal bothropic envenomation in horses from Central Western Brazil in order to contribute to the correct diagnosis of this condition. A survey of the records of equine necropsies from the Veterinary Pathology Laboratories of the University of Brasilia, Federal University of Mato Grosso and Federal University of Mato Grosso do Sul, from January 2010 to February 2018, was performed. Five fatal cases of bothropic snakebite were identified in 755 necropsies of horses, corresponding to 0.66% of these cases, ranging annually from 0.33% to 0.89%. The main necropsy findings were marked swelling and diffuse subcutaneous hemorrhage, and identification of the fang marks in 2 out of five horses. Hemorrhage in most organs and tissues was the pathological hallmark of systemic envenomation. Myonecrosis, dermonecrosis, and moderate to severe kidney degeneration and necrosis were also observed. Fatal Bothrops snakebites in horses have a low occurrence in Central Western Brazil and most cases occur in the rainy season. The diagnosis of this condition may be substantiated by clinical signs and pathological findings. Local hemorrhage and necrosis, systemic hemorrhagic disorders and injuries related to acute kidney injury are the predominant clinical signs. These findings should be considered in the diagnosis and therapeutic management of these envenomations.

Putative parapoxvirus-associated foot disease in the endangered huemul deer (Hippocamelus bisulcus) in Bernardo O'Higgins National Park, Chile.

The huemul (Hippocamelus bisulcus) is an endangered cervid endemic to southern Argentina and Chile. Here we report foot lesions in 24 huemul from Bernardo O'Higgins National Park, Chile, between 2005 and 2010. Affected deer displayed variably severe clinical signs, including lameness and soft tissue swelling of the limbs proximal to the hoof or in the interdigital space, ulceration of the swollen tissues, and some developed severe proliferative tissue changes that caused various types of abnormal wear, entrapment, and/or displacement of the hooves and/or dewclaws. Animals showed signs of intense pain and reduced mobility followed by loss of body condition and recumbency, which often preceded death. The disease affected both genders and all age categories. Morbidity and mortality reached 80% and 40%, respectively. Diagnostics were restricted to a limited number of cases from which samples were available. Histology revealed severe papillomatous epidermal hyperplasia and superficial dermatitis. Electron microscopy identified viral particles consistent with viruses in the Chordopoxvirinae subfamily. The presence of parapoxvirus DNA was confirmed by a pan-poxvirus PCR assay, showing high identity (98%) with bovine papular stomatitis virus and pseudocowpoxvirus. This is the first report of foot disease in huemul deer in Chile, putatively attributed to poxvirus. Given the high morbidity and mortality observed, this virus might pose a considerable conservation threat to huemul deer in Chilean Patagonia. Moreover, this report highlights a need for improved monitoring of huemul populations and synergistic, rapid response efforts to adequately address disease events that threaten the species.

Tropical Keratopathy (Florida Spots) in Cats.

The authors used microscopy and synchrotron-based small-angle X-ray scattering analysis (SAXS) to describe lesions macroscopically typical of tropical keratopathy ("Florida spots") from 6 cats on St Kitts. Microscopically, there were varying degrees of epithelial hyperplasia and thinning of the cornea (by 4% to 18%) due to loss of corneal stroma associated with dense accumulations of collagen in the superficial stroma. The collagen fibrils in lesions were wider and had more variable diameters (39.5 ± 5.0 nm, mean ± SD) than in normal corneas (25.9 ± 3.6 nm; P < .01). There were occasional vacuoles (<1 µm) in the corneal epithelial basement membrane but no evidence of inflammation, edema, stromal neovascularization, fibrosis, acid-fast organisms, or structures suggestive of a fungal organism. SAXS analysis showed collagen fibril diameters and variation in size were greater in stroma containing the lesions compared to normal corneas (48.8 ± 4.5 nm vs 35.5 ± 2.6; P < .05). The d-spacing of collagen in the stroma of lesions and normal corneas was the same, but the average orientation index of collagen in lesions was greater (0.428 ± 0.08 vs 0.285 ± 0.03; P < .05). A survey revealed Florida spots lesions were static over time and became less obvious in only 1 of 6 affected cats adopted on St Kitts and taken to areas in the US where lesions are not reported. An anterior stromal collagen disorder with various degrees of epithelial hyperplasia is the pathologic hallmark of lesions clinically identical to Florida spots in cats from St Kitts.

A Case of Prototheca zopfii Genotype 1 Infection in a Dog (Canis lupus familiaris).

Protothecosis is a rare disease caused by environmental algae of the genus Prototheca. These are saprophytic, non-photosynthetic, aerobic, colorless algae that belong to the Chlorellaceae family. Seven different species have been described. Prototheca zopfii genotype 2 and P. wickerhamii are most commonly involved in pathogenic infections in humans and animals. The objective of this work is to describe, for the first time, a case of protothecosis caused by P. zopfii genotype 1 in a dog. The dog, a 4-year-old mix bred male, was presented to a veterinary clinic in Montevideo, Uruguay, with multiple skin nodules, one of which was excised by surgical biopsy. The sample was examined histologically and processed by PCR, DNA sequencing, and restriction fragments length polymorphisms for the detection and genotyping of P. zopfii. In addition, transmission electron microscopy and scanning electron microscopy were performed. Histology showed severe ulcerative granulomatous dermatitis and panniculitis with myriads of pleomorphic algae. Algal cells were 4-17 µm in size, with an amphophilic, 2-4-µm-thick wall frequently surrounded by a clear halo, contained flocculant material and a deeply basophilic nucleus, and internal septae with daughter cells (endospores) consistent with endosporulation. Ultrastructurally, algal cells/endospores at different stages of development were found within parasitophorous vacuoles in macrophages. Prototheca zopfii genotype 1 was identified by molecular testing, confirming the etiologic diagnosis of protothecosis.

Experimental and iatrogenic poisoning by sodium selenite in pigs / Intoxicação iatrogênica e experimental por selenito de sódio em suínos

Following a case of iatrogenic selenium poisoning in a young pig, an experimental study was carry out. Sodium selenite was orally and parenterally administered to 13 pigs that were subdivided into three groups (G1, G2 and G3). The animals in groups G1 and G3 received sodium selenite intramuscularly (IM), G1 received a comercial formula, and G3 received sodium selenite mixed with distilled water at different dosages, and those in group G2 were fed commercial sodium selenite. Acute and subacute poisoning was observed in both groups, although the onset of clinical signs was slower in group G2. Only one pig (in group G1) that had received the highest dose showed a peracute course. Apathy, anorexia, dyspnea, vomiting, muscular tremors, proprioceptive deficit, ataxia and paresis of the hind limbs progressing to the front limbs evolving to tetraplegia were observed. Postmortem findings differed whether the animals received the injected (G1 and G3) or oral (G2) sodium selenite. The liver was moderately atrophic in some animals of G2. Some of the animals in groups G1 and G3 presented with lung edema. One pig in G3 had yellowish-brown areas in the ventral horns of the cervical intumescences of the spinal cord. The most important histological changes were present in the ventral horns of the cervical and lumbar intumescences of the spinal cord. In one animal, changes were present in the brainstem and mesencephalon. The initial lesion was a perivascular and astrocyte edema that progressing to lysis and death of astrocytes and neurons. In the chronic stage of the lesions, there were extensive areas of liquefaction necrosis with perivascular lymphocytic and histiocytic infiltration and occasional eosinophils. It seems that disruption of the blood-brain barrier due to astrocyte edema is the most likely mechanism of CNS lesion.(AU)

A partir de um caso de intoxicação iatrogênica por selenito de sódio injetável em suíno verificaram-se alguns aspectos patogenéticos não esclarecidos, o que ensejou o estudo experimental. Selenito de sódio foi administrado pelas vias oral e parenteral a 13 suínos, subdivididos em três grupos (G1, G2 e G3). Os grupos G1 e G3 receberam selenito de sódio por via intra-muscular (IM); (G1 - fórmula comercial e G3 - selenito de sódio misturado à água destilada, em diversas dosagens) e o grupo G2, por via oral (VO), misturado à ração. Quadros de evolução aguda e subaguda foram observados em todos os grupos, embora o início dos sintomas tenha sido mais lento no grupo G2. Um único porco (do grupo G1), que havia recebido a dose mais alta, apresentou evolução superaguda. Apatia, anorexia, dispneia, vômito, tremores musculares, déficit proprioceptivo, ataxia e paresia dos membros posteriores com progressão para os anteriores e evolução para tetraplegia foram observados. Os achados de necropsia foram diferentes entre os animais que receberam o selenito de sódio injetável (IM - G1 e G3) e oral (G2). Havia moderada atrofia hepática em alguns animais do G2. Parte dos animais dos grupos G1 e G3 apresentaram edema pulmonar. Em um suíno (G3) notaram-se áreas marrom-amareladas nos cornos ventrais da intumescência cervical. As alterações histológicas mais importantes ocorreram nos cornos ventrais do "H" medular das intumescências cervical e lombar. Em um animal, as alterações envolviam o tronco cerebral e o mesencéfalo. Inicialmente, a lesão caracterizava-se por edema perivascular e astrocitário que progredia para lise e necrose de astrócitos e neurônios. O estágio crônico das lesões caracterizava-se por extensas áreas de necrose liquefativa e infiltração perivascular linfocítica e histiocítica, com raros eosinófilos. Sugere-se que a ruptura da barreira hematoencefálica por edema astrocitário seja o mecanismo mais provável da lesão no SNC.(AU)

Immunohistochemical, lectin histochemical and ultrastructural studies of canine transmissible venereal tumor in Brazil / Estudos imuno-histoquímico, lectino-histoquímico e ultraestrutural do Tumor Venéreo Transmissível Canino no Brasil

Canine transmissible venereal tumor (CTVT) is a naturally occurring contagious round-cell neoplasia, with poorly understood origin and transmission. This study aims to further investigate the tumor nature through immunohistochemistry, lectin histochemistry and transmission electron microscopy (TEM) analysis, and to provide support for diagnostic and differential diagnoses of CTVT. Immunohistochemistry was performed in 10 genital and six exclusively extragenital tumors, which were previously diagnosed by citology and histopathology. CTVT samples were incubated with biotinylated antibodies to specific membrane and cytoplasmic antigens (anti-lysozyme, anti-macrophage, anti-vimentin, anti-CD18, monoclonal anti-CD117, monoclonal anti-CD3, polyclonal anti-CD117, polyclonal CD3 and anti-CD79a), followed by the avidin-biotin-peroxidase complex technique. The lectins Con A, DBA, SBA, PNA, UEA-1, WGA, sWGA, GSL, JSA, PSA, PHA-L, PHA-E and RCA were additionally tested in four genital CTVTs and TEM was performed in eight genital tumors. The anti-vimentin antibody revealed strong immunoreactivity to neoplastic cells in all the assessed samples (16/16). The polyclonal anti-CD3 antibodies showed moderate to strong immunoreactivity in fourteen (14/16) and the polyclonal anti-CD117 in fifteen cases (15/16). There was no immunoreactivity to anti-lysozyme, anti-macrophage, anti-CD18, monoclonal anti-CD117, monoclonal anti-CD3 and anti-CD79a antibodies. At lectin histochemistry, it was observed strong staining of tumor cells to Con-A, PHA-L and RCA. There was no histopathological and immunoreactivity differences between genital and extragenital CTVTs. These findings do not support the hypothesis of histiocytic origin of CTVT. In contrast, the lectin histochemical results were similar to cells from lymphoid/myeloid origin.(AU)

O Tumor Venéreo Transmissível Canino (CTVT) é uma neoplasia de células células redondas, contagiosa, com origem e transmissão ainda mal compreendidas. Com a finalidade de aprofundar a investigação sobre a natureza (origem) do TVTC, bem como fornecer subsídios para o estabelecimento do diagnóstico e diagnóstico diferencial, realizaram-se avaliações imuno-histoquímica, lectino-histoquímica e ultraestrutural de TVTC(s). A avaliação imuno-histoquímica foi feita em 10 TVTCs genitais e em 6 exclusivamente extragenitais previamente diagnosticados através de citologia e da histopatologia. Os TVTCs foram testados para reagentes específicos de antígenos de membrana e citoplasmáticos (anti-lisozima, anti-macrófago, anti-vimentina, anti-CD18, anti-CD3, anti-CD79, anti-CD117) com utilização da técnica complexo avidina-biotina-peroxidase. Adicionalmente, foram utilizadas as lectinas Con A, DBA, SBA, PNA, UEA-1, WGA, sWGA, GSL, SJA, PSA, PHA-L, PHA-E e RCA em quatro TVTCs genitais. Microscopia eletrônica foi realizada em oito TVTC genitais. Em 100% dos tumores testados (16/16) com anticorpo anti-vimentina (mono e policlonal) houve forte imuno-reatividade. Não houve reatividade para os anticorpos anti-lisozima, anti-macrófago, anti-CD18, anti-CD3, anti-CD79a e anti-CD117 quando empregamos anticorpos monoclonais, entretanto, com a utilização de anticorpos policlonais verificou-se marcação dos tumores com os anticorpos anti-CD3 e anti-CD117. Na avaliação lectino-histoquímica foi verificada forte marcação das células tumorais com Con-A, PHA-L e RCA. Não houve diferença histopatológica e de imuno-reatividade entre os TVTCs genitais e extragenitais. Estes achados não corroboram com a hipótese da origem histiocítica do CTVT (ausência de reatividade dos anticorpos anti-lisozima, anti-macrófago e anti-CD18), entretanto, os resultados da avaliação lectino-histoquímica foram em parte similares aos obtidos quando células de origem linfóide/mielóide (ConA, PHA-L e RCA) foram analisadas (Gimeno et al. 1995).(AU)