Pathological aspects of cutaneous mast cell tumors with metastases in 49 dogs.

Cutaneous mast cell tumor (MCT) is one of the most frequent cutaneous neoplasms of dogs and may vary from well-differentiated to aggressive tumors with metastasis. The authors retrospectively described the gross and histologic aspects of metastatic MCT in 49 dogs. Primary MCT was most commonly identified in the inguinal region (14/35; 40%), and at necropsy multiple, cutaneous nodules were frequently reported (23/49; 47%). All primary MCT were classified as high-grade neoplasms, and metastases involved the lymph nodes (47/49; 96%), spleen (33/49; 67%), liver (29/49; 59%), bone marrow (20/49; 41%), kidneys (16/49; 33%), and heart (14/49; 29%), while the lungs were less commonly affected (9/49; 18%). The main gross findings included lymphadenomegaly in 47 cases; splenomegaly in 28 cases, with splenic nodules in 13 dogs; hepatomegaly in 28 cases, with white pinpoint foci in 9 cases; nodules on the capsular surface of the kidneys in 9 dogs; and epicardial nodules in 6 cases. Histologically, the lymph nodes were largely obliterated by neoplastic mast cells, while in the spleen, neoplastic cells were multifocally scattered (16/33; 48%), arranged in nodules (10/33; 30%), or obliterated the parenchyma (9/33; 27%). In the liver, the neoplastic cells mainly infiltrated the sinusoids (24/29; 83%), but were also arranged in random nodules (10/29; 34%). Interstitial and nodular metastases were observed in the kidneys and the heart. Grossly unapparent metastases were common in the heart (6/14; 43%), kidneys (4/16; 25%), and lungs (6/9). KIT III and KIT II staining patterns were observed in 29 and 20 cases, respectively.

Rangelia vitalii in free-living crab-eating foxes (Cerdocyon thous) in Uruguay.

Rangelia vitalii is a protozoan parasite that causes a hemorrhagic and hemolytic disease in dogs known as rangeliosis. Current reports of the disease are concentrated in the southern and southeastern regions of Brazil, as well as in Uruguay, Argentina, and Paraguay, and mainly concern domestic dogs. South American wild canids, such as the crab-eating fox (Cerdocyon thous), the pampas fox (Lycalopex gymnocercus), and the maned wolf (Chrysocyon brachyurus) may also be affected, although existing reports are restricted to Brazil. The present study aimed to detect R. vitalii parasitism in the Uruguayan wild fox population. DNA extracted from the blood and/or spleen samples of road-killed C. thous and L. gymnocercus found in northern Uruguay were subjected to polymerase chain reaction (PCR) to amplify a 551-bp fragment of the Rangelia 18S rRNA gene. A total of 62 wild canids, including 38 C. thous and 24L. gymnocercus, were analyzed. Five crab-eating fox samples (13.2%) were positive for R. vitalii, with 99.5-100% identity between the sequences. All samples from pampas fox tested negative for R. vitalii. When compared with the R. vitalii sequences available in GenBank, a similarity of 98.9-100% was revealed. Molecular analysis results suggest that R. vitalii is circulating in the crab-eating fox population in Uruguay; however, its veterinary relevance for these foxes remains unknown.

Rangelia vitalii molecular and histological quantification in tissues comparing crab-eating foxes (Cerdocyon thous) and domestic dogs.

Rangeliosis is a condition transmitted by the tick Amblyomma aureolatum and caused by the protozoan parasite Rangelia vitalii in canids. In domestic dogs, the disease causes a severe hemolytic disease, while in wild canids the piroplasm is often detected without any clinical abnormality. This study aimed to detect and quantify the number of copies of the R. vitalii Hsp70 gene (indirect parasite burden) in several organs of domestic and South American wild canids (Cerdocyon thous and Lycalopex gymnocercus) to elucidate distinct clinical presentations of rangeliosis in these species. A total of seven domestic dogs that died due to rangeliosis and 38 wild foxes were initially included, with all dogs presenting histological and molecular features of rangeliosis, while eight C. thous were positive at the molecular analysis for R. vitalii. Fragments of 22 organs collected from domestic (n = 7) and wild foxes (n = 8) were employed for histological and molecular quantification using real-time polymerase chain reaction aiming at the Hsp70 gene. Histologically, parasitophorous vacuoles were constantly detected in the dogs, while these were detected only in two C. thous. Parasitic burden was significantly higher in the digestive, cardiorespiratory, endocrine, genitourinary, and skeletal-muscle systems of domestic dogs when compared to wild foxes. In the hematopoietic system of wild canids, some organs, such as the lymph nodes and tonsils, presented significantly lower amounts of R. vitalii, while other organs (spleen, bone marrow, and blood) had results similar to those of domestic dogs. Additionally, the central nervous system of both domestic and wild canids presented a similar quantity of R. vitalii. The etiological agent is possibly maintained through an asexual reproductive process (merogony) in both domestic and wild species. Nonetheless, a limited or short-duration schizogony phase occurs in C. thous, which would designate this species as a possible reservoir host for the agent. Dogs, in contrast, would most likely act as accidental hosts, presenting a severe and more pathogenic schizogony phase, resulting in characteristic clinical and pathological rangeliosis.

Congestive heart failure in a young cat with excessive moderator bands (false tendons) in the left ventricle / Insuficiência cardíaca congestiva em um gato jovem com bandas moderadoras excessivas (falsos tendões) em ventrículo esquerdo

ABSTRACT: Left ventricular false tendons are fibrous or fibromuscular bands that transverse the ventricular cavity and have no attachment to the mitral valve in many species. In cats it is considered a congenital defect that is rarely related to clinical disease and death in adult cats. A 45 days-old mixed breed cat had a history of inappetence since birth. At the physical exam the patient was lethargic and presented restrictive dyspnoea. At necropsy, there were marked ascites, hydrothorax, hepatomegaly with enhanced lobular pattern (nutmeg liver), and the lungs were markedly diminished (compressive pulmonary atelectasis). The heart was enlarged due to marked dilation of the cardiac chambers. Moreover, multiple slightly whitish and irregular cord-like structures were connecting the posterior papillary muscle to the interventricular septum (excessive moderator bands /left ventricular false tendons) at the left ventricle. Microscopically, these structures were characterized by a marked proliferation of fibrous connective tissue intermixed with Purkinje cells and well-differentiated cardiomyocytes lined by a single layer of endocardium. This study described a case of excessive moderator bands (left ventricular false tendons) in a young cat associated with congestive heart failure and death.

RESUMO: Falsos tendões são bandas fibrosas ou fibromusculares que atravessam a cavidade do ventrículo esquerdo, sem ligação com a valva mitral, em várias espécies. Nos gatos, a alteração é considerada um defeito congênito que raramente está relacionada com alterações clínicas e morte em gatos adultos. Um gato de 45 dias de idade, sem raça definida e com histórico de inapetência desde o nascimento foi encaminhado para atendimento veterinário. Ao exame físico apresentou letargia e dispneia restritiva. À necropsia, havia acentuada ascite, hidrotórax, hepatomegalia com evidenciação do padrão lobular (fígado noz-moscada) e os pulmões apresentavam-se acentuadamente diminuídos (atelectasia pulmonar compressiva). O coração apresentava acentuada dilatação das câmaras cardíacas. Em ventrículo esquerdo, havia numerosas estruturas brancacentas semelhantes a cordas conectando o músculo papilar ao septo interventricular (bandas moderadoras excessivas/falsos tendões). Microscopicamente, estas estruturas apresentavam acentuada proliferação de tecido conjuntivo fibroso, além de células de Purkinje e cardiomiócitos bem diferenciadas revestidas por uma única camada de endocárdio. O objetivo deste trabalho é descrever um caso de bandas moderadoras excessivas (falsos tendões) em ventrículo esquerdo de um gato jovem com insuficiência cardíaca congestiva e morte.

Spina bifida, diplomyelia and multiple malformations in a Texel lamb / Espinha bífida, diplomielia e múltiplas malformações em um cordeiro Texel

ABSTRACT: This report described the clinical and pathological aspects of open spina bifida and diplomyelia along with multiple congenital malformations in a Texel lamb. Clinically, paresis of the thoracic limbs, paralysis of the pelvic limbs and a cutaneous opening in the lumbosacral region were observed. At necropsy, there was a focally extensive disruption of the skin associated with an absence of the dorsal portions of the lumbosacral vertebrae. Additionally, diplomyelia of the lumbar segment, mild hydromyelia of thoracic segment, and moderate communicating hydrocephalus of the lateral and third ventricles were noted. Possible viral etiologies (bovine viral diarrhea virus, bluetongue virus, and Schmallemberg virus) were not detected by RT-PCR, and toxic plants were not identified. Therefore, a possible genetic cause may not be discarded.

RESUMO: Este trabalho descreve os aspectos clínicos e patológicos de um caso de espinha bífida aberta e diplomielia, além de múltiplas malformações, em um cordeiro Texel. Clinicamente, este apresentava paresia de membros torácicos, paralisia dos membros pélvicos e uma abertura cutânea na região lombossacral desde o nascimento. À necropsia, visualizou-se solução de continuidade na pele e ausência das porções dorsais das vértebras lombossacrais. Além disso, observou-se diplomielia em segmento lombar, hidromielia discreta de segmento torácico e hidrocefalia comunicante moderada de ventrículos laterais e terceiro ventrículo. Possíveis etiologias virais (vírus da diarreia viral bovina, vírus da língua azul e Schmallemberg virus) não foram detectadas através de RT-PCR, e possíveis plantas tóxicas não foram identificadas. Portanto, uma causa genética não pode ser descartada.

Epidemiological and pathological aspects of salmonellosis in cattle in southern Brazil / Aspectos epidemiológicos e patológicos de salmonelose em bovinos no Sul do Brasil

ABSTRACT: Salmonellosis is a bacterial disease that affects several domestic animal species, and is commonly diagnosed in cattle, horses, and pigs. This study aimed to describe the epidemiological and pathological findings of eleven cases of enteric salmonellosis and two cases of salmonellosis with pulmonary involvement in cattle in Rio Grande do Sul State, Brazil. Clinical signs included fever, yellow diarrhea, sometimes with blood streaks, and dyspnea, with a clinical course ranging from 1 to 30 days. Eight cases occurred as outbreaks, whereas five cases occurred individually. Risk factors included inadequate handling practices, such as overcrowded facilities and comorbidities, including anaplasmosis. The main gross finding of the enteric presentation was fibrinonecrotic enterocolitis, occasionally associated with button ulcers, mesenteric lymphadenomegaly, splenomegaly, cholecystitis and hepatomegaly. In addition, one steer with a chronic clinical progression presented severe segmental thickening of the ileum, associated with intestinal rupture and peritonitis. In the respiratory system, the main findings were reddened, non-collapsed lungs, with multifocal areas of atelectasis. The main microscopic findings were observed in the small and large intestines, and these were characterized by severe necrosis and mucosal ulceration, associated with marked inflammatory infiltrate of neutrophils and fibrin deposition intermixed by rod-shaped bacterial aggregates, and fibrosis, as well as interstitial pneumonia. Seven cases yielded positive bacterial cultures for Salmonella spp. and three serovars, namely Typhimurium, Dublin, and Panama were identified. All cases exhibited immunolabeling for Salmonella spp. using immunohistochemistry.

RESUMO: Salmonelose é uma doença bacteriana que afeta inúmeras espécies animais, especialmente os bovinos, os equinos e os suínos. O presente estudo teve como objetivo descrever os aspectos epidemiológicos e patológicos de onze casos de salmonelose entérica e dois de salmonelose pulmonar em bovinos no estado do Rio Grande do Sul, Brasil. Os sinais clínicos incluíram febre, diarreia amarelada, por vezes com estrias de sangue, anorexia, perda de peso e dispneia, com curso clínico que variou de um a 30 dias. Em oito casos, a doença ocorreu em forma de surtos e cinco foram individuais. Identificou-se fatores de risco relacionados ao manejo inadequado com os bovinos, como alta lotação, além de comorbidades associadas, como anaplasmose. Os principais achados macroscópicos da forma entérica consistiram em enterocolite fibrinonecrótica, por vezes associada a formação de úlceras botonosas, linfonodos mesentéricos e baço aumentados, colecistite e hepatomegalia. Ainda, um bovino com quadro clínico crônico apresentou acentuado espessamento segmentar da parede do íleo associado a ruptura intestinal e peritonite. Na forma respiratória, os principais achados incluíram pulmões não colabados, avermelhados, com áreas multifocais de atelectasia. Os principais achados microscópicos foram observados no intestino delgado e grosso e foram caracterizados por acentuada necrose e ulceração da mucosa, associada a acentuado infiltrado inflamatório de neutrófilos e deposição de fibrina entremeada por agregados bacterianos cocobacilares e fibrose, além de pneumonia intersticial. Sete casos foram positivos para Salmonella sp. no cultivo bacteriano, com identificação dos sorovares Typhimurium, Dublin e Panama. Ao exame imuno-histoquímico para Salmonella sp. todos os casos apresentaram marcação positiva nos órgãos avaliados.

Pathological, immunohistochemical, and molecular findings of equine protozoal myeloencephalitis due to Sarcocystis neurona infection in Brazilian horses.

Equine protozoal myeloencephalitis (EPM) is an important neurologic disease of horses in the American continent caused by Sarcocystis neurona and Neospora hughesi infection. This study describes the pathological, immunohistochemical, and molecular findings of fatal cases of EPM in southern Brazil. A review was performed on a total of 13 cases compatible with EPM, which were diagnosed by postmortem examination in the period of 2010-2017. Epidemiological information was obtained from necropsy reports. Gross and histological lesions were characterized, and cases were subjected to immunohistochemistry anti-Sarcocystis neurona, Toxoplasma gondii, and Neospora spp. Molecular search was performed using ITS-1 gene PCRs. Microscopic lesions were multifocal in all cases, and more frequently observed in the spinal cord segments and in the rhombencephalon. Intralesional protozoans were histologically detected in five horses, while a positive immunostaining for S. neurona was observed in eleven cases (11/13). Through molecular techniques, six positive cases for the ITS-1 gene were detected, and obtained sequences presented highest similarity with S. neurona. EPM due to S. neurona infection represents an important neurologic disease of horses in Brazil and this disease should be considered as a main differential diagnosis in horses presenting neurologic signs.

Clinical and pathological aspects of first report of Tunga penetrans infestation on southern brown howler monkey (Alouatta guariba clamitans) in Rio Grande do Sul, Brazil.

BACKGROUND: Tungiasis is a neglected neotropical disease caused by penetration of Tunga spp. into the skin of the host. METHODS: Two primates were rescued from nearby different indigenous villages, and the clinical, pathological, and parasitological features of tungiasis were described. Flea identification occurred through their morphometry and was confirmed with the use of a dichotomous key. RESULTS: Monkey 1 was parasitized by 23 sand fleas and, after treatment, was assigned to the animal rehabilitation center. Monkey 2 was in poor body condition and died shortly after clinical examination. At necropsy, this primate was parasitized by 26 specimens of sand fleas. CONCLUSIONS: Both animals altered their tree behavior by staying on the ground for long periods. This parasitic relationship implies the possibility of enlargement of the sand flea dispersion. Thus, this is the first record of Tunga penetrans occurrence in wild Alouatta guariba clamitans.

Atypical parasitic lesions in slaughtered cattle in Southern Brazil.

In this study, we described the morphological features and unusual presentations of hydatidosis, fasciolosis, and eosinophilic myositis caused by Sarcocystis species diagnosed at the slaughterhouse lines. Twenty-seven samples of atypical parasitic lesions from distinct cattle were evaluated, of which 12 corresponded to hydatidosis, 11 to fasciolosis, and 4 to eosinophilic sarcocystosis. Hydatid cysts were observed mainly in the heart, with all cases involving the left ventricle. Fasciolosis lesions involved mainly the lungs, and were characterized by a focal nodular elevated area involving the edges of the lobes. Intralesional trematodes were observed in three cases. Sarcocystosis lesions were observed in four cases, and lesions were primarily located in the skeletal and cardiac muscles. Grossly, they presented as focal or focally extensive streaks, patches, or numerous nodules that were greenish to mildly yellowish. Histologically, all the cases had intralesional ruptured cysts of Sarcocystis that were associated with severe eosinophilic myositis and myocarditis. Parasitic lesions in atypical locations and/or with aberrant responses should be promptly identified because it may mistakenly diagnosed as other potentially zoonotic diseases, such as cysticercosis and tuberculosis.

Mycobacterium tuberculosis var. tuberculosis infection in two captive black capuchins (Sapajus nigritus) in Southern Brazil.

Tuberculosis is a common zooanthroponosis in humans with a high incidence in Brazil, but it may also affect non-human primates (NHPs), of which Old World primates are most commonly involved. Nonetheless, its occurrence in New World primates is unknown, and therefore, this study aimed to describe the infection by Mycobacterium tuberculosis variant tuberculosis in two captive black capuchin monkeys (Sapajus nigritus) in Southern Brazil. The primates were housed in the same enclosure, wherein close contact with humans frequently occurred, and presented apathy, anorexia, and death in a clinical course of 15 days to 2 months. At the necropsy, the tracheobronchial lymph nodes were markedly enlarged and firm to hard and on the cut surface had a caseous aspect. The lungs exhibited two injury patterns: multifocal and disseminated. Microscopically, the lungs exhibited multifocal to coalescing necrotic granulomas and non-necrotic granulomas, with multiple acid-fast bacilli within the cytoplasm of epithelioid macrophages and multinucleated giant cells. Bacilli were also labeled upon immunohistochemistry (IHC) for Mycobacterium tuberculosis. Microbiological culture of lung samples from both cases yielded colonies compatible with M. tuberculosis. The isolates were identified as M. tuberculosis var. tuberculosis through polymerase chain reaction (PCR). Although tuberculosis is poorly described in New World primates, M. tuberculosis var. tuberculosis may cause a highly contagious and progressive disease with high mortality in black capuchin monkeys (S. nigritus).

Rhizopus microsporus segmental enteritis in a cow.

A ten year-old Holstein cow had an intermittent bloody diarrhea, evolving to anorexia and recumbency, followed by death. Mycotic segmental enteritis was diagnosed based on the pathological and immunohistochemical findings. Rhizopus microsporus was identified as the causal agent through fungal culture and PCR analysis. Intestinal mucormycosis is poorly described in cattle and should, therefore, be included as a differential diagnosis in cases of diarrhea and death in ruminants, especially when there is disruption of the normal balance of the alimentary microbiota.

Acute renal failure in a horse following bee sting toxicity / Insuficiência renal aguda associada à intoxicação por picadas de abelhas em um cavalo

ABSTRACT: Bee envenomation is frequent in humans and dogs, but uncommon in horses. This study aimed to describe a case of acute renal failure following mass envenomation in a horse. A mare was attacked by a swarm of bees and showed reluctance to move, epistaxis, and dark-brown urine. Biochemical exams revealed increase in urea and creatine serum levels. The mare did not respond to treatment and euthanasia was elected after four days of clinical course. At the necropsy, there were multifocal pinpoint to elevated skin lesions associated with edema and hemorrhage, which extended to the subcutaneous tissue and skeletal muscle, and the kidneys were diffusely dark-brown and friable. Microscopically, renal tubules were distended and filled with an orange-red, hyaline globular material, and had severe epithelial tubular cell necrosis. The diagnosis was established based on clinical and histological analysis, and pathological evaluation was essential to confirm acute renal failure due to bee sting toxicity.

RESUMO: Acidentes por picada de abelhas são frequentemente descritos em humanos e cães, entretanto relatos em cavalos são escassos. Este trabalho teve como objetivo descrever um caso de insuficiência renal aguda em um equino após múltiplas picadas de abelhas. Uma égua foi atacada por um enxame de abelhas desenvolvendo quadro clínico de relutância em se movimentar, epistaxe e urina marrom-escura. Exames bioquímicos demonstraram aumento nos níveis séricos de ureia e creatina. O equino não respondeu ao tratamento e a eutanásia foi realizada após quatro dias de curso clínico. Na necropsia havia múltiplas elevações cutâneas, que ao corte exibiam edema e hemorragia, os quais se estendiam ao subcutâneo e musculatura adjacente. Os rins estavam difusamente marrom-escuros e havia friáveis. Microscopicamente, os túbulos renais estavam distendidos e preenchidos por um material hialino, globular, laranja-avermelhado e havia acentuada necrose das células epiteliais tubulares. O diagnóstico foi obtido por meio da análise clínica e histológica, e a avaliação patológica foi essencial para confirmar a insuficiência renal aguda por picada de abelha.

Hypertrophic osteopathy in a cat with cardiac interventricular septal defect.

A 3-year-old mixed-breed female cat was diagnosed with a ventricular septal defect of the heart through an echocardiogram. After a 9-month treatment, progressive and diffuse hard thickening of all limbs was observed, which on radiographic examinations, revealed a marked thickening of the long bones. The necropsy findings were limited to the appendicular skeleton and thoracic vertebrae, in addition to a severe cardiac interventricular septal defect and lung edema. The histological evaluation revealed severe replacement of the cortical bone by spongy bone in all bone fragments examined. This is the first report of hypertrophic osteopathy occurring in association with a cardiac malformation in a cat.

Fatal parasite-induced enteritis and typhlocolitis in horses in Southern Brazil.

Diseases related to the alimentary system are the main cause of death in horses. This retrospective study aimed to describe the pathological findings of fatal parasite-induced enteritis and typhlocolitis caused by cyathostominae, Eimeria leuckarti, Balantidium coli, and Strongyloides westeri in horses. The records of parasite-induced intestinal lesions in horses necropsied in Southern Brazil between 2005 and 2017 were reviewed. Ten horses had fatal parasitic enteritis and/or typhlocolitis, and the main causes were: cyathostominae typhlocolitis (6/10), E. leuckarti enteritis (1/10), S. westeri enteritis (1/10), B. coli colitis related to cyathostominae (1/10), and infection by multiple agents (1/10). Cyathostominae typhlocolitis showed marked mucosal thickening, with multifocal elevated nodules containing tangled filiform parasites. Microscopic examination revealed that the mucosa and submucosa had encysted parasitic structures surrounded by eosinophilic and granulomatous inflammation. E. leuckarti enteritis was microscopically characterized by macrogamonts, microgamonts, and oocysts inside the host cells. S. westeri enteritis showed microscopic atrophy of the villi with numerous mucosal encysted parasitic structures. B. coli typhlocolitis showed severe diffuse mucosal reddening, with microscopic superficial mucosal necrosis associated with multiple protozoan trophozoites. Fatal parasite-induced enteritis and typhlocolitis are important causes of death in horses in Southern Brazil.

Fatal parasite-induced enteritis and typhlocolitis in horses in Southern Brazil / Enterites e tiflocolites parasitárias fatais em equinos no Sul do Brasil

Abstract Diseases related to the alimentary system are the main cause of death in horses. This retrospective study aimed to describe the pathological findings of fatal parasite-induced enteritis and typhlocolitis caused by cyathostominae, Eimeria leuckarti, Balantidium coli, and Strongyloides westeri in horses. The records of parasite-induced intestinal lesions in horses necropsied in Southern Brazil between 2005 and 2017 were reviewed. Ten horses had fatal parasitic enteritis and/or typhlocolitis, and the main causes were: cyathostominae typhlocolitis (6/10), E. leuckarti enteritis (1/10), S. westeri enteritis (1/10), B. coli colitis related to cyathostominae (1/10), and infection by multiple agents (1/10). Cyathostominae typhlocolitis showed marked mucosal thickening, with multifocal elevated nodules containing tangled filiform parasites. Microscopic examination revealed that the mucosa and submucosa had encysted parasitic structures surrounded by eosinophilic and granulomatous inflammation. E. leuckarti enteritis was microscopically characterized by macrogamonts, microgamonts, and oocysts inside the host cells. S. westeri enteritis showed microscopic atrophy of the villi with numerous mucosal encysted parasitic structures. B. coli typhlocolitis showed severe diffuse mucosal reddening, with microscopic superficial mucosal necrosis associated with multiple protozoan trophozoites. Fatal parasite-induced enteritis and typhlocolitis are important causes of death in horses in Southern Brazil.

Resumo Doenças relacionadas ao sistema alimentar são as principais causas de morte em equinos. Esse estudo teve o objetivo de descrever aspectos patológicos de enterites e tiflocolites parasitárias fatais por ciatostomíneos, Eimeria leuckarti, Balantidium coli e Strongyloides westeri, em equinos. Foi revisado o banco de dados de lesões intestinais parasitárias em equinos necropsiados de 2005 a 2017, no Sul do Brasil. Dez equinos apresentaram enterite e/ou tiflocolite parasitária fatal, e as principais foram: tiflocolite por ciatostomíneos (6/10), enterite por E. leuckarti (1/10), enterite por S. westeri (1/10), colite por B. coli com ciatostomíneos (1/10), e infecção por múltiplos agentes (1/10). A tiflocolite por ciatostomíneos exibia acentuado espessamento da mucosa, com nódulos multifocais elevados contendo parasitas filiformes. Microscopicamente, a mucosa e submucosa apresentavam estruturas parasitárias encistadas envoltas por inflamação eosinofílica e granulomatosa. A enterite por E. leuckarti era caracterizada microscopicamente por macrogamontes, microgamontes e oocistos no interior de células do hospedeiro. Microscopicamente, a enterite por S. westeri apresentava atrofia de vilosidades com numerosas estruturas parasitárias encistadas na mucosa. A tiflocolite por B. coli exibia avermelhamento acentuado difuso da mucosa, e microscopicamente necrose superficial associada a múltiplos trofozoítos protozoáricos. Enterites e tiflocolites fatais parasitárias são importantes causas de morte em equinos no Sul do Brasil.

Pathological and virological features of skin lesions caused by BVDV in cattle.

Dermatitis might occur in mucosal disease (MD) caused by bovine viral diarrhea virus (BVDV). This study describes the pathological and virological features of skin lesions associated with BVDV infection in four persistently infected (PI) cattle. Skin samples were reprocessed for histopathology and IHC. BVDV isolates were obtained and were genetically characterized. In addition to upper alimentary system ulcerative lesions, all cattle (one outbreak and three individual cases) presented focal crusty and ulcerative lesions affecting the mucocutaneous and skin-horn junctions, interdigital clefts, pastern, and areas surrounding the dewclaws and diffuse thickened skin within 7-20 days of infection. Microscopic analysis revealed parakeratotic hyperkeratosis and single-cell keratinocyte death, accompanied by ballooning degeneration and spongiosis in the epidermis, as well as intraepithelial and subcorneal pustules. IHC showed BVDV antigen in the cytoplasm of keratinocytes undergoing individual cell death. Phylogenetic analysis revealed that the isolates from cattle #1, #2, and #4 belonged to BVDV-1a, whereas that from cattle #3 belonged to BVDV-1d. Cytopathic BVDV was isolated from cattle #2 and #3 (MD), and non-cytopathic BVDV was isolated from cattle #1 and #4. Thus, BVDV infection might cause acute disease, characterized by skin and upper alimentary system ulcerative lesions, in both MD and PI cattle.

Pathological and molecular characterization of avian malaria in captive Magellanic penguins (Spheniscus magellanicus) in South America.

Avian malaria is a mosquito-borne disease that affects multiple avian species and is caused by protozoans of the genus Plasmodium. An avian malaria infection caused by Plasmodium sp. in Magellanic penguins (Spheniscus magellanicus) with high mortality is described in a zoo in Southern Brazil. Clinically, three birds presented signs of inappetence, anorexia, pale mucosa, dyspnea, and opisthotonus, with death in a clinical course of 5-8 h. At the necropsy, all birds exhibited pale mucosa, marked splenomegaly and hepatomegaly, in addition to moderate leptomeningeal blood vessels ingurgitation in the brain. Microscopically, multiple exoerythrocytic meronts were observed in the cytoplasm of endothelial cells in the spleen, liver, heart, lungs, brain, kidneys, and pancreas. The spleen had a multifocal perivascular inflammatory infiltrate of lymphocytes, plasma cells, and macrophages, which also exhibited hemosiderosis and erythrophagocytosis. The liver had a multifocal periportal inflammatory infiltrate of lymphocytes, macrophages, and plasma cells, in addition to marked hemosiderosis in the hepatic sinusoids. Fragments of spleen, liver, brain, skeletal muscle, and lung were tested by the polymerase chain reaction technique for the detection of a fragment of the cytochrome B gene from haemosporidians, which resulted positive for Plasmodium spp. After sequencing, the samples were phylogenetically associated to Plasmodium sp. detected in Turdus albicollis (KU562808) in Brazil and matched to the lineage TURALB01 previously detected in T. albicollis. Avian malaria infections caused by Plasmodium sp. of lineage TURALB01 may occur in S. magellanicus with high mortality, and, thus, it is essential to detect and characterize the agent involved to obtain the differential diagnosis of the condition.

Cholesteatoma and hydrocephalus associated to a third ventricle meningioma in a cat / Colesteatoma e hidrocefalia associados a meningioma em terceiro ventrículo em um gato

ABSTRACT: Meningiomas are neoplasms that commonly involve the central nervous system of cats, while cholesteatomas are nodular granulomatous chronic lesions within the choroid plexus that are rarely reported in cats. This study described a case of cholesteatoma and non-communicating hydrocephalus associated to a third ventricle meningioma in a cat. Clinically, the cat had a 2-year history of behavioral changes, photophobia and motor incoordination. At the necropsy, a tan-brown mass totally occluded the third ventricle, causing a severe dilation of the lateral ventricles (non-communicating hydrocephalus). Microscopically, the mass was composed by a neoplastic proliferation of spindle cells arranged in bundles, containing in the center psammomatous bodies (meningioma), while in the adjacent areas a cholesteatoma was observed, which was characterized by multiple cholesterol cleft formation, hemosiderosis and associated granulomatous inflammation. At immunohistochemistry (IHC), neoplastic cells had a marked immunostaining for vimentin, while were negative for cytokeratin and S100. The diagnosis of transitional meningioma occurring in association to cholesteatoma and non-communicating hydrocephalus in a cat was obtained mainly by the histological and IHC features. These are important methods to distinguish this condition from other neurological disorders in cats.

RESUMO: Meningiomas são neoplasias que comumente envolvem o sistema nervoso central de gatos, enquanto colesteatomas são formações nodulares granulomatosas raramente descritas nessa espécie e que resultam de lesões crônicas em plexo coroide. O objetivo desse trabalho é descrever um caso de meningioma em terceiro ventrículo culminando com a formação de colesteatoma e hidrocefalia não comunicante em um gato. Clinicamente, o gato apresentava alteração de comportamento, fotofobia e incoordenação motora durante dois anos. À necropsia apresentava uma massa acastanhada no terceiro ventrículo que provocava oclusão total do mesmo e acentuada dilatação de ventrículos laterais (hidrocefalia não comunicante). Microscopicamente, havia proliferação neoplásica de células fusiformes arranjadas em feixes com a formação de corpos psamomatosos (meningioma), e em área adjacente havia múltiplas fendas de colesterol e hemossiderose com infiltrado granulomatoso (colesteatoma). À imuno-histoquímica (IHQ), foi observada marcação positiva para vimentina e negativa para citoqueratina e S100 nas células neoplásicas. Os exames histológicos e de IHQ contribuíram para a confirmação do diagnóstico de meningioma transicional associado à formação de colesteatoma e hidrocefalia não comunicante, e são métodos importantes para diferenciar de outras afecções que cursam com quadro clínico neurológico em felinos.

Multilocus characterization of Sarcocystis falcatula-related organisms isolated in Brazil supports genetic admixture of high diverse SAG alleles among the isolates.

In a previous study in Brazil, six isolates of Sarcocystis spp. recovered from budgerigars fed sporocysts excreted by opossums of the genus Didelphis were characterized by means of sequencing fragments of gene coding cytochrome B (CYTB), internal transcribed spacer 1 (ITS1), and surface antigen genes (SAG2, SAG3 and SAG4). The isolates shared identical ITS1 and CYTB sequences, but differed at SAG2, SAG3 and SAG4: three allele variants of SAG2, 3 allele variants of SAG3 and 2 allele variants of SAG4 were encountered in three multilocus genotypes (MLGs) (MLG1, MLG2, and MLG3). At ITS1 and CYTB, all the isolates from budgerigars were identical to the Sarcocystis falcatula-like isolate 59-2016-RS-BR that was detected in a barefaced ibis (Phimosus infuscatus) causing necrotizing meningoencephalitis in Brazil. At ITS1 locus, all the above isolates were clearly distinct from Sarcocystis neurona, Sarcocystis falcatula, Sarcocystis lindsayi, and Sarcocystis speeri, the four known species of Sarcocystis that use opossums of the genus Didelphis as definitive hosts. Here, we replicated the experiment above to identify additional MLGs or other species of Sarcocystis. Fifteen budgerigars were experimentally infected with sporocysts of Sarcocystis spp. from 12 opossums of the genus Didelphis. All the birds died 9-19 days after infection and tissue samples containing merozoites and schizonts of Sarcocystis spp. were recovered. Fractions of sequences coding for 18S ribosomal RNA gene (18S), CYTB, ITS1, SAG2, SAG3 and SAG4 were PCR amplified and sequenced from the infected lungs. In addition, fractions of 18S, SAG2, SAG3 and SAG4 were sequenced from the isolate 59-2016-RS-BR and fractions of 18S were sequenced from the six isolates from budgerigars described above. From the results, all the isolates shared identical 18S, ITS1 and CYTB sequences. Among the 15 new isolates from budgerigars, three allele variants of SAG2, 3 allele variants of SAG3 and 2 allele variants of SAG4 were encountered in five MLGs, of which four were novel (MLG1, MLG4, MLG5, MLG6 and MLG7). Isolate 59-2016-RS-BR was assigned to an eighth MLG (MLG8). Molecular data pointed that Sarcocystis assigned to MLGs 1 to 8 are variants of the same species, but the SAG-based trees of the isolates conflicted, which supports genetic admixture among them. The sarcocystinae studied have high diversity of SAG alleles per locus and the correlation of such an abundant variety of SAG alleles to host specificity and pathogenicity needs to be assessed. Remains to be elucidated if the parasites studied here and S. falcatula are variants of the same species that have diverged to the point of possessing differences at ITS1 level, but that are still capable of exchanging genes.

Fibrinous pleuropneumonia caused by Pasteurella multocida associated with bovine lymphoma / Pleuropneumonia fibrinosa causada por Pasteurella multocida associada a linfoma bovino

ABSTRACT: In this work, we describe an unusual case of fibrinous pleuropneumonia caused by Pasteurella multocida associated with generalized lymphadenomegaly in a bovine. The animal had a one-month history of generalized superficial lymphadenomegaly that progressed to anorexia and submandibular oedema, resulting in spontaneous death. At necropsy, the parenchyma of the lymph nodes and multiple organs was obliterated by a dense proliferation of round neoplastic cells (lymphoma). Additionally, the neoplasm presented multifocal areas of haemorrhage and necrosis, characteristic of lymphoma. The parietal and visceral pleura and parietal pericardium were enlarged and covered diffusely with large amounts of a yellowish fibrillary material. The lungs were mildly enlarged, non-collapsed, and firm and exhibited interlobular septae that were thickened with a gelatinous material. Histopathological examination showed that the parietal and visceral pleura were enlarged due to a diffuse and severe inflammatory infiltrate composed of degenerate neutrophils associated with severe fibrin deposition, characteristic of fibrinous pleuropneumonia. Pleura and parietal pericardium fragments were cultivated in aerobic and microaerobic microbiological conditions. Round greyish colonies of gram-negative coccobacilli that were shiny and non-haemolytic were observed in sheep blood agar. The biochemical profile was indicative of Pasteurella spp. Molecular identification was performed by partial 16S rRNA amplification following sequencing. Pasteurella multocida was confirmed as the primary bacterium associated with the bovine fibrinous pleuropneumonia. We are able to infer that the lymphoma caused immunodepression, which increased the animal's susceptibility to atypical infectious microorganisms such as pathogenic P. multocida.

RESUMO: Nesse trabalho, relatamos um caso de pleuropneumonia fibrinossupurativa causada por Pasteurella multocida associada à linfoadenomegalia em um bovino. O animal apresentava aumento generalizado de linfonodos há um mês progredindo para anorexia e edema submandibular por três dias culminando com óbito. Durante a necropsia, tanto dos linfonodos quanto de diversos órgãos evidenciaram proliferação neoplásica de células arredondadas e arranjadas em mantos (linfoma). Adicionalmente, áreas multifocais de hemorragia e necrose, características de linfoma, foram observadas. As pleuras parietal e visceral e pericárdio parietal apresentavam-se espessas e recobertas por acentuada quantidade de fibrina. Os pulmões estavam aumentados, não colabados, firmes e exibiam espessamento com edema moderado de septos interlobulares. À microscopia, cortes da pleura visceral exibiram acentuado infiltrado inflamatório de neutrófilos degenerados com intensa deposição de fibrina, características da pleuropneumonia fibrinossupurativa, além de neovascularização e proliferação de fibroblastos. Amostras de pulmão e da pleura foram cultivadas em aerobiose e microaerobiose. Evidenciou-se o crescimento puro no ágar sangue ovino de colônias redondas, acinzentadas, brilhantes e não-hemolíticas, sendo caracterizadas como cocobacilos gram-negativos. As características bioquímicas do isolado foram condizentes com Pasteurella spp. Procedeu-se a identificação molecular do isolado através da amplificação parcial do gene rRNA 16S com posterior sequenciamento do produto amplificado. Deste modo foi possível a confirmação do isolado como Pasteurella multocida, sendo o agente primário da pleuropneumonia fibrinosa. Com estes dados, podemos afirmar que o linfoma causou um quadro de imunodepressão, a qual aumenta a susceptibilidade dos animais a agentes infecciosos atípicos, como a P. multocida patogênica.