Molossinema wimsatti infection in the brain of Pallas's mastiff bats (Molossus molossus).

The present report describes two cases of infection by Molossinema wimsatti in the brain of Pallas's mastiff bats (Molossus molossus). The first bat was captured and killed by a domestic cat in a suburban area of the municipality of Patos, Paraiba, northeastern Brazil. The second bat was found crawling on the ground in the same area before dying. No gross lesions were found at necropsy. Histology of the central nervous system revealed filarioid nematodes in the brain ventricles and cerebellum. There were adults, subadults and eggs, the latter sometimes containing microfilariae. No inflammatory response was observed in bat 1, while bat 2 presented a mild lymphoplasmacytic meningoencephalitis. Three nematodes were recovered and submitted for parasitological examination. The diagnosis of M. wimsatti infection was based on the histomorphological and parasitological characteristics of the agent and its location in the brain ventricular system of insectivorous bats. The infection likely occurs in other insectivorous bats from South American and Caribbean countries but may be overlooked.

Poisoning by Enterolobium contortisiliquum pods in calves showing photosensitization and digestive lesions / [Lesões digestivas e fotossensibilização em bezerros intoxicados pelas favas de Enterolobium contortisiliquum]

Este trabalho descreve um surto de rumenite e abomasite decorrente de sobrecarga de carboidratos em um rebanho de 238 bezerros, com idades entre 12 e 15 meses, causada pela ingestão dos frutos de Enterolobium contortisiliquum. As taxas de morbidade, mortalidade e letalidade foram de, respectivamente, 12,7%, 5,2% e 42,1%. Clinicamente, os bovinos apresentaram fotossensibilização, salivação e diarreia. Os achados de necropsia foram semelhantes nos dois bezerros necropsiados e consistiram de fotodermatite e rumenite ulcerativa multifocal, subaguda a crônica, e abomasite. A relevância deste relato é que, pela primeira vez, foi possível associar a ocorrência da rumenite devido à sobrecarga de carboidratos com a intoxicação espontânea por E. contortisiliquum em bovinos, confirmando achados anteriormente descritos em experimentos realizados com ovinos.(AU)

Congenital Segmental Absence of Tracheal Rings in a Kitten.

Congenital anomalies of the trachea are rare in cats. This article reports segmental absence of tracheal cartilage rings in a kitten. An 8-month-old female kitten was presented with a history of weight loss and respiratory distress for 2 months. Radiographs of the thorax demonstrated a large air-filled sac suggestive of pneumomediastinum. No cartilaginous structures were evident radiographically over the caudal portion of the trachea. At necropsy examination, approximately 2 cm from the carina, a 3 cm segment of the trachea lacked cartilaginous rings. The clinical and morphological features of this lesion were similar to those described in human and canine cases of congenital segmental absence of tracheal rings.

Neurotoxicosis in horses associated with consumption of Trema micrantha.

BACKGROUND: Trema micrantha is a tree widely distributed throughout the Americas. The tree produces highly palatable leaves that have been associated with natural poisoning in goats, sheep and horses, in which hepatic necrosis and hepatic encephalopathy have been observed. OBJECTIVES: This study describes malacia and haemorrhage in the central nervous system (CNS) due to T. micrantha consumption, with minimal to absent hepatic lesions. STUDY DESIGN: Retrospective case series. METHODS: A total of 14 horses with a history of neurological signs and spontaneous consumption of T. micrantha leaves were submitted to necropsy and multiple samples were collected for histopathology. Details of clinical history and signs of the horses were obtained through inquiries to the owners and attending veterinarians. RESULTS: All the 14 horses had neurological signs of ataxia, severe sialorrhoea, involuntary running movements, sternal and lateral recumbency, and death after a clinical course that lasted from 24 h to 9 days. For a few days prior to onset of clinical signs, all horses had spontaneously consumed, potentially toxic doses of T. micrantha leaves. All 14 brains had diffuse yellowish discoloration affecting the rhombencephalon, mesencephalon, diencephalon, telencephalon and corpus striatum. In all cases, the most severe lesions were observed in the pons. Spinal cord lesions were observed affecting the lumbar intumescence, which was swollen with darken and depressed areas at the dorsal and ventral horns, and at the sacral level, which on cut surface displayed a friable and yellowish grey matter. The lesions observed grossly in brain and spinal cord consisted microscopically of severe vasculitis and liquefactive necrosis of white and grey matter of the brainstem, cerebellum and spinal cord. MAIN LIMITATIONS: This is a small retrospective series relying on clinical observations reported by owners and attending veterinarians. The mechanism of action of the plant toxin in the CNS is still unidentified. CONCLUSION: T. micrantha poisoning in horses causes predominantly a neurological disease, with minimal to absent hepatic lesions.

Necrotizing meningoencephalitis in a cow.

An 18-month-old Charolais cow developed depression and drooling and was submitted for necropsy after euthanasia. The cow was 1 of 50 moved between 2 farms approximately 5 days before the onset of clinical disease. Gross findings included swollen and hemorrhagic areas of malacia in the frontal, temporal, and parietal lobes of the cerebral cortex. Microscopically there was a necrotizing meningoencephalitis with intranuclear astrocytic and neuronal eosinophilic viral inclusions in the frontal, temporal, and parietal cerebral cortex as well as in the basal nuclei and thalamus. The gross and microscopic findings were consistent with necrotizing meningoencephalitis caused by bovine herpesvirus (BHV-1 or BHV-5), and the diagnosis was confirmed by detection of bovine herpesviral antigen on fresh samples of brain via fluorescent antibody test using a monoclonal antibody against BHV-1 glycoprotein C.

Defeitos congênitos em bovinos da Região Central do Rio Grande do Sul / Congenital defects in cattle from central Rio Grande do Sul, Brazil

Foram revisados casos de defeitos congênitos (DCs) diagnosticados em bovinos no Laboratório de Patologia da Universidade Federal de Santa Maria em 1964-2010. Durante o período estudado, foram examinados materiais provenientes da necropsia de 7.132 bovinos e foram encontrados 31 bezerros (0,4 por cento) com DCs, os quais foram classificados em 34 tipos e alocados nos sistemas orgânicos primariamente afetados. Os DCs ocorriam isoladamente (19 [61,3 por cento]) ou afetavam múltiplos sítios anatômicos (15 [28,7 por cento]) com frequência semelhante em ambos os sexos. Como vários terneiros mostraram múltiplos DCs, um total de 53 DCs foi computado. Dos 53 DCs diagnosticados, 15 (28,3 por cento) afetavam o sistema nervoso central (craniósquise [4], abiotrofia cerebelar [2], degeneração esponjosa [2], hidrocefalia [2], meningocele [2], espinha bífida [1], hipoplasia cerebelar [1] e hipomielinogênese [1]); nove (17,0 por cento) afetavam o sistema urogenital (agenesia testicular [1], agenesia vaginal [1], hipoplasia peniana [1], formação de cloaca [1], freemartinismo [1], hamartoma vascular de ovário [1], hipoplasia renal [1], cistos renais [1] e úraco persistente [1]); oito DCs (15,1 por cento) eram primários do sistema musculoesquelético (artrogripose [4], escoliose [1], plagiocefalia, [1] schistosomus reflexus [1] e diprosopia [1]); e outros oito (15,1 por cento) foram alocados no sistema digestivo (palatosquise [3], atresia anal [1], atresia anorretal [1], atresia - anocolônica [1], fístula reto-vaginal [1] e fístula reto-uretral [1]); em cinco ocasiões (9,4 por cento) o DC afetava o sistema cardiovascular (persistência do ducto arterioso [2], persistência do forame oval [2] e defeito do septo ventricular [1]); quatro (7,5 por cento) afetavam o sistema linfático e consistiam de hipoplasia ou aplasia de vasos linfáticos e linfonodos associadas a linfedema. Dois casos (3,4 por cento), de hipotricose foram observados afetando o integumento; um caso (1,9 por cento) de estenose traqueal foi encontrado no sistema respiratório e um caso (1,9 por cento) de bócio envolvia o sistema endócrino. Os resultados indicam que a maioria dos DCs em bovinos na Região Central do Rio Grande do sul é esporádica. No entanto, seu estudo continuado é importante para o estabelecimento de sua etiologia e controle.

Cases of congenital defects (CDs) in cattle diagnosed at the Laboratory of Veterinary Pathology of the Federal University of Santa Maria from 1964 to 2010 were reviewed. During the studied period tissues collected from the necropsy of 7,132 cattle were examined and 31 calves (0.4 percent) with CDs were found. These CDs were classified into 34 different types and ascribed to the body system primarily affected. CDs were solitary (19 [61.3 percent]) or multiple (12 [38.7 percent]) and found with similar frequency in calves of both sexes. As several calves displayed multiple defects, a total of 53 CDs were computed. Out of the 53types of CDs diagnosed 15 (28.3 percent) affected the central nervous system (cranioschisis [4], cerebellar abiotrophy [2], spongy degeneration [2], hydrocephalus [2], meningocele [2], spina bifida [1], cerebellar hypoplasia [1], and hypomyelinogenesis [1]); nine (17.0 percent) affected the urogenital system (testicular agenesis [1], vaginal agenesia [1], penile hypoplasia [1], cloacal formation [1], freemartinism [1], ovarian vascular hamartoma [1], renal hypoplasia [1], renal cysts [1], and persistent urachus [1]); eight CDs (15,1 percent) were primary to the musculoskeletal system (arthrogryposis [4], scoliosis [1], plagiocephaly [1] schistosomus reflexus [1], and diprosopus [1]) and another eight (15,1 percent) were in the digestive system (palatoschisis [3], anal atresia [1], anorectal atresia [1], ano-colonic atresia [1], recto-vaginal fistula [1], and recto-urethral fistula [1]); in five instances (9.4 percent) the CD affected the cardiovascular system (persistent ductus arteriosus [2], persistence of foramen ovale [2], and ventricular septal defect [1]); four (7.5 percent) affected the lymphatic system and consisted of inherited hypoplasia or aplasia of lymphatic vessels and lymph nodes associated with lymphedema. Two cases (3.0 percent), of hypotrichosis were observed affecting the integument; one case (1.9 percent) of tracheal stenosis was found in the respiratory system and one case of goiter (1.9 percent) involved the endocrine system. The results of this survey inidicate that the majority o CDs in cattle in the central Rio Grande do Sul are sporadic; nevertheless their continued study is important for determining the etiology and control.

A retrospective study of 586 tumours in Brazilian cattle.

Records from 6,706 necropsy examinations of cattle performed over a 45-year period were surveyed and 586 cases of neoplasia were identified. The organ system most frequently affected by neoplastic disease (n=139 cases) was the alimentary tract. This finding was attributed to a high incidence of squamous cell carcinoma of the upper alimentary tract associated with the chronic ingestion of bracken fern (Pteridium aquilinum). This carcinogenic plant was also associated with a relatively high incidence (n=35 cases) of urinary bladder tumours (enzootic haematuria). Tumours of the alimentary tract were followed, in decreasing order of frequency, by tumours of the skin and subcutis (n=129 cases), haemopoietic tissue (n=101 cases), the eye and periorbital tissues (n=88 cases), the urinary system (n=44 cases), the female reproductive system (n=21 cases), the endocrine system (n=16 cases), the liver and pancreas (n=12 cases), the nervous system (n=6 cases), the respiratory system (n=6 cases) and the mammary gland (n=1 case). The primary anatomical location of 16 tumours was undetermined.

Morphological factors as indicators of malignancy of squamous cell carcinomas in cattle exposed naturally to bracken fern (Pteridium aquilinum).

Squamous cell carcinomas (SCCs) of the upper digestive tract (UDT) of cattle have been associated with chronic bracken fern (Pteridium aquilinum) toxicity and infection with bovine papillomavirus type-4. These tumours share some morphological similarities with human head and neck SCCs. In this study, morphological changes were correlated with the biological behaviour of 40 alimentary SCCs in cattle grazing on pastures with high bracken content. The majority of SCCs were localized to the cranial and caudal regions of the UDT (almost 45% each). More than 60% of the tumours were well differentiated and were found mostly in the cranial region. Metastasis occurred in 58% of the cases, mostly to regional lymph nodes. All poorly differentiated SCCs had evidence of metastasis. Morphological patterns characterized by islands and ribbons of neoplastic keratinocytes were more prominent in well differentiated SCCs. These patterns varied greatly in moderately differentiated SCCs. Poorly differentiated tumours were characterized by the presence of cellular aggregates and individual cells and these tumours had more marked desmoplasia. A significant positive association was established between lymphoplasmacytic inflammatory infiltration and tumour-associated tissue eosinophilia. Evaluation of argyrophylic nucleolar organizer regions (AgNORs) revealed higher proliferation indices in poorly differentiated tumours than in moderately or well differentiated lesions. There was significant correlation between the AgNOR index and histological grading. The morphological factors analyzed were all related to histological grading, which is the major factor predicting the biological behaviour of SCCs in cattle naturally exposed to bracken fern.

Neuropathology of naturally occurring Trypanosoma evansi infection of horses.

The clinical signs and pathology of the central nervous system in 9 horses with naturally occurring neurologic disease due to Trypanosoma evansi are described. The clinical course was 2 to 20 days; clinical signs included marked ataxia, blindness, head tilt and circling, hyperexcitability, obtundity, proprioceptive deficits, head pressing, and paddling movements. Grossly, asymmetric leukoencephalomalacia with yellowish discoloration of white matter and flattening of the gyri were observed in the brain of 7 of 9 horses. Histologically, all 9 horses had necrotizing encephalitis that was most severe in the white matter, with edema, demyelination, and lymphoplasmacytic perivascular cuffs. Mild to moderate meningitis or meningomyelitis was observed in the spinal cord of 5 of 7 horses. T. evansi was detected immunohistochemically in the perivascular spaces and neuropil of formalin-fixed, paraffin-embedded brain tissue in 8 of 9 horses.

Alterações oftálmicas associadas à intoxicação experimental por closantel em caprinos / Ophthalmic changes associated with the experimental poisoning by closantel in caprine

Alterações oftálmicas foram experimentalmente induzidas em caprinos após superdosagem com o anti-helmíntico closantel. Foram usados cinco caprinos com sete a oito meses de idade, produtos do cruzamento da raça Saanen com a Pardo Alpino. Os animais mostraram sinais de intoxicação entre quatro e cinco dias após a administração do closantel. Os sinais clínicos caracterizaram-se principalmente por distúrbios neurológicos centrais e cegueira. Ao exame clínico, observaram-se midríase bilateral, perda do reflexo pupilar à luz e cegueira bilateral. À oftalmoscopia indireta, foram observadas degeneração aguda de retina e papiledema. As alterações crônicas mostravam disco óptico acinzentado, atrofia de vasos e da retina. Nos fundos tapetal e não-tapetal notavam-se áreas de despigmentação e lesões irregulares castanho-amareladas. As alterações histológicas consistiam em perda dos neurônios da camada ganglionar e das células da camada nuclear interna e externa da retina. As alterações agudas no nervo óptico e na substância branca do encéfalo foram de degeneração espongiforme. As alterações crônicas do nervo óptico caracterizavam-se por extensa necrose e infiltração de células Gitter.

Ophthalmic alterations were experimentally induced after overdose with the anthelmintic closantel. Five seven to eight- months-old, Saanen x Alpine caprine were used. The animals showed clinical signs of toxicosis four to five days after the administration of closantel. Clinical signs were primarily characterized by central nervous disturbances and blindness. Clinically, bilateral mydriasis, loss of pupillary light reflex, and blindness were observed. At indirect ophthalmoscopic examination, there was acute retinal degeneration and papilledema. Chronic ocular changes consisted of paleness of the optic disc, vascular atrophy, and retinal atrophy. Areas of pigment loss and irregular yellowish-brown foci were present in the tapetal and non-tapetal fundus. Histological alterations consisted of neuronal loss in the ganglion cell layer and depletion of cells in both the outer and inner nuclear layers of the retina. Acute changes of spongy degeneration were noted in the optic nerve and in the cerebral white matter. Chronic lesions in the optic nerve were characterized by extensive necrosis and infiltration by Gitter cells.

Outbreaks of tetanus in beef cattle and sheep in Brazil associated with disophenol injection.

Outbreaks of tetanus, in which 297 beef cattle and 50 sheep were affected and died, were associated with the injection of a Clostridium tetani-contaminated anthelmintic (disophenol). The disease was observed on five farms in Rio Grande Sul, Brazil.

Papillary adenocarcinoma of the extrahepatic bile duct in a Holstein cow.

A 15-year-old female Holstein cow was presented with a history of anorexia and weight loss. Abnormal physical examination findings included poor body condition, dehydration, icterus, and photodermatitis on nonpigmented areas of the skin of the dorsum. At necropsy, the common bile duct was greatly enlarged, with thickened walls, and tightly adhered to the hepatic capsular surface and serosa of adjacent loops of the small intestine. Two sessile, yellowish, friable, well-circumscribed, cauliflower-like, bulging masses (14 and 8 cm in diameter) were attached to the inner surface of the common bile duct blocking its lumen. Microscopically, the tumor was composed of well-differentiated, columnar epithelial cells with oval or round, vesicular, basal nuclei arranged in papillary projections. Periodic acid-Schiff-positive material accumulated in the apical cytoplasm of the neoplastic cells. Immunostaining of the tumor cells was positive for cytokeratin (CK) of wide-spectrum screening and for CK 7. The diagnosis of papillary adenocarcinoma of the extrahepatic bile duct was based on the morphologic features of the neoplasm and evidence of local invasion. To the best of our knowledge, extrahepatic bile duct carcinomas have not been described in cattle.

Alteraçöes ultra-estruturais do miocárdio na intoxicaçäo experimental de coelhos pela planta calcinogênica Solanum malacoxylon / Ultrastructural changes in the myocardium in the experimental poisoning of rabbits by calcinogenic plant Solanum malacoxylon

Seis coelhos com cerca de três meses, de ambos os sexos, receberam via sonda gástrica, extrato aquoso de Solanum malacoxylon equivalente a 100 mg de folhas dessecadas por kg de peso vivo. Dois animais näo receberam o extrato e serviram como testemunhas, sendo sacrificados ao final do experimento. Entre 48, 72 e 120 horas após o início do experimento, todos os outros coelhos foram sacrificados e fragmentos do miocárdio foram processados para microscopia óptica e eletrônica. As alteraçöes macroscópicas mais importantes foram estrias esbranquiçadas no miocárdio, particularmente no átrio esquerdo. Em microscopia óptica, grupos de células musculares mostravam sarcoplasma tumefeito, com perda das estriaçöes, discreta basofilia e eventualmente vacuolizaçöes do sarcoplasma. Estas células geralmente estavam rodeadas por macrófagos, células mesenquimais e alguns polimorfonucleares neutrófilos de permeio com material necrótico. No interstício foi evidenciado material basofílico finamente granular. A reaçäo de von Kossa nestes locais revelou depósitos de cálcio no sarcoplasma dos miócitos, no interstício e, eventualmente, ao redor de células musculares aparentemente näo lesadas. Os vasos coronários exibiam mineralizaçäo da média. Na ultra-estrutura foram observadas: ativaçäo dos cardiomiócitos e das células intersticiais, deposiçäo do cálcio no interstício e no sarcoplasma das células musculares cardíacas e no cistoplasma de células intersticiais. Em fases mais avançadas observou-se necrose dos cardiomiócitos, com mineralizaçäo das células e lise celular. Alguns polimorfonucleares neutrófilos e macrófagos fagocitando material necrótico mineralizado säo também vistos nestes locais. O aspecto morfológico do miocárdio sugere que as lesöes de necrose e calcificaçäo säo o resultado da açäo direta do 1,25(OH)2D3 contido na planta sobre as células do miocárdio. Os animais testemunhas näo exibiram alteraçöes no miocárdio

Seneciose em bovinos / Seneciosis in cattle

Säo apresentados dados epidemiológicos, clínicos, de necropsia e histopatológicos acumulados durante o estudo de 15 surtos espontâneos de intoxicaçöes por Senecio spp (maria-mole) em bovinos, ocorridos nos últimos três anos no Rio Grande do Sul. A morbidade média foi de 17% e a mortalidade de, praticamente, 100%. O pico das mortes ocorreu durante os meses de primavera e início do veräo. Devido ao caráter crônico da intoxicaçäo, casos esporádicos ocorreram ao longo do ano.

Intoxicaçäo crônica por cobre em ovinos / Chronic coopper poisoning in sheep

Säo descritos dois surtos de intoxicaçäo crônica por cobre em ovinos no Rio Grande do Sul, causando a morte de pelo menos 21 animais. O s sinais clínicos incluíam depressäo, anorexia, icterícia e homoglobinúria; as mortes ocorrem 4 a 6 dias apòs o início dos sintomas. As lesöes mais consistentes vistas na necrópsia foram icterícia, fígado amarelo ou alaranjado, rins escuros e tumefeitos. O diagnóstico foi confirmado pelos altos níveis de cobre encontrados na raçäo e em fragmentos de fígado e rim dos animais afetados