Fabiana M. Boabaid

An outbreak of aflatoxin poisoning in dogs associated with aflatoxin B1–contaminated maize products

An aflatoxicosis outbreak affected 65 dogs from 9 different farms after they were fed diets with cooked corn meal as a common ingredient. Of the dogs, 60 died. Numerous dogs died on additional farms, but those dogs were not included in the study. The farmers acquired the contaminated maize products, in the form of whole corn grain or as corn meal, from the same supplier. The corn product was mixed with meat that was left over from home or commercial rations to form corn polenta, which was fed to the dogs. Necropsy was performed on 3 dogs. Two of the dogs died after a few days of refusing food, showing anorexia, polydipsia, icteric mucous membranes, hematemesis, hematochezia, or melena, and bleeding of the skin, eye, ear, and mouth. The primary necropsy findings included jaundice, hemorrhages in several organs, and yellowish enlarged liver with enhanced lobular pattern. The dog that experienced chronic ascites had a yellowish liver with reduced volume, irregular surface, and increased consistency. The main histological findings included hepatocyte fatty degeneration, biliary duct hyperplasia, cholestasis and, in the chronic case, hepatic fibrosis. High-performance liquid chromatography analysis of the corn meal from 2 affected farms revealed 1,640 ppb and 1,770 ppb of aflatoxin B1, respectively. The current study demonstrates an additional way that dogs can be exposed to, poisoned, and killed by aflatoxin.

Clinical and pathological insights into Johne′s disease in buffaloes

Alternative diagnostic tools and interesting epidemiological assumptions were associated with an outbreak of Johne′s disease. In a buffalo herd infected with paratuberculosis, seven clinically affected animals and 21 animals with anti-Mycobacterium avium ELISA reactions were identified. Total herd included 203 buffaloes. Most lesions were comparable to those described in buffaloes and cattle affected by Johne′s disease. Water buffalo behaviors such as communal nursing and allosuckling may be additional risk factors for this disease. Detection of positive Ziehl–Neelsen staining and anti-M. avium immunolabeling in rectal biopsies from one buffalo with paratuberculosis are highlighted as auxiliary diagnostic tools for Johne′s disease in live animals.

Alpha-mannosidosis in goats caused by the swainsonine-containing plant Ipomoea verbascoidea

A disease of the nervous system is reported in goats in the semiarid region of northeastern Brazil. Histological examination showed diffuse vacuolation of neurons and epithelial cells of the pancreas, thyroid, renal tubules, and liver. The swainsonine-containing plant Ipomoea verbascoidea was found on both farms where the goats originated. This plant was experimentally administered to 3 goats, inducing clinical signs and histologic lesions similar to those observed in spontaneous cases. On the lectin histochemical analysis, cerebellar cells and pancreatic acinar cells gave positive reactions to Triticum vulgaris agglutinin (WGA), succinylated Triticum vulgaris agglutinin (sWGA), Lens culinaris agglutinin (LCA), Canavalia ensiformis agglutinin (ConA), Pisum sativum agglutinin (PSA), Ricinus communis agglutinin (RCA120), Arachis hypogaea agglutinin (PNA), and Phaseolus vulgaris erythroagglutinin (PHA-E) suggesting storage of α-fucose, α-D-mannose, α-D-glucose, β-D-N-acetyl-glucosamine, N-acetyl-galactosamine, and acetyl-neuraminic acid. This pattern of lectin staining partially agrees with results previously reported for poisoning by swainsonine-containing plants. The chemical analysis of dried leaves of I. verbascoidea detected swainsonine (0.017%), calystegine B1 (0.16%), calystegine B2 (0.05%), and calystegine C1 (0.34%). It is concluded that I. verbascoidea causes α-mannosidosis in goats.

Granulomatous Meningoencephalitis Due to Toxoplasma gondii in a Black-headed Night Monkey (Aotus nigriceps)

Abstract This report describes toxoplasmosis infection in a black-headed night monkey (Aotus nigriceps) from the Zoological Park of the Federal University of Mato Grosso, Brazil. The animal was submitted alive to the Veterinary Hospital of the Federal University of Mato Grosso presenting neurologic clinical signs. There were no improvements on the animals clinical condition after treatment, so it was euthanized. At necropsy, the most significant gross lesions observed were hemorrhages diffusely scattered throughout the cerebral hemispheres. Histologic findings were characterized by nonsuppurative encephalitis and mild multifocal necrotizing nonsuppurative myocarditis. Groups of tachyzoites and cysts were observed surrounding the inflamed areas of cerebral parenchyma. Sections of the brain were submitted for immunohistochemistry examination for Toxoplasma gondii and Neospora caninum and also for polymerase chain reaction (PCR) to determine the presence of Toxoplasma gondii. The samples were positive for Toxoplasma gondii by PCR; however, cross reactivity was observed between Toxoplasma gondii and Neospora caninum antibodies. These findings were consistent with a toxoplasmosis infection in this animal.

Characterization of pantropic canine coronavirus from Brazil

Abstract Characterization of canine coronavirus (CCoV) strains currently in circulation is essential for understanding viral evolution. The aim of this study was to determine the presence of pantropic CCoV type IIa in tissue samples from five puppies that died in Southern Brazil as a result of severe gastroenteritis. Reverse-transcriptase PCR was used to generate amplicons for sequence analysis. Phylogenetic analysis of the CCoV-IIa strains indicated that they were similar to those found in other countries, suggesting a common ancestor of these Brazilian isolates. This is the first report of pantropic CCoV-II in puppies from Latin America and our findings highlight that CCoV should be included as a differential diagnosis when dogs present with clinical signs and lesions typically seen with canine parvovirus infection.

OUTBREAK OF TYPE C BOTULISM IN CAPTIVE WILD BIRDS

Abstract:  In late summer 2010, an outbreak of type C botulism affected the birds kept in a dam at a southern Brazilian zoo. A total of 14 (10 black-necked swans, Cygnus melancoryphus; 3 Muscovy ducks, Cairina moschata; and 1 fulvous whistling-duck, Dendrocygna bicolor) out of 100 birds died after showing flaccid paralysis of the skeletal muscles characterized by general locomotion deficit, flight and swimming disorders, dropped neck, and severe dyspnea. Carcasses of dead birds (some infested by larvae of sarcophagus fly) scattered in the bird enclosure, and oxygen-free, organically rich mud and/or shallow standing waters present at the edges of the weir were identified as possible toxin sources. Postmortem examinations revealed no significant pathological changes. Epidemiologic and clinical findings indicated the diagnosis of type C botulism toxin, which was confirmed by mouse bioassay and seroneutralization.

Fatal systemic toxoplasmosis in Valley quail (Callipepla californica)

Highlights • This is the first report of systemic fatal toxoplasmosis in Valley quail.• Toxoplasma gondii was molecularly identified as belonging to ToxoDB-PCR-RFLP #87.• It caused a generalized disease with necrotic lesion in liver, heart, spleen, lungs, trachea and bone marrow, with large numbers of tachyzoites stained positively with polyclonal antiserum to T. gondii.

Intoxicação espontânea por Cestrum intermedium em bovinos no Sudoeste do Estado do Paraná

Sao descritos surtos de intoxicacao espontânea por Cestrum intermedium em bovinos leiteiros do Municipio de Salgado Filho, sudoeste do Estado do Parana, com morte de dezesseis bovinos de um total de 72 de quatro pequenas propriedades. O historico obtido nessas propriedades incluia curso clinico agudo, com morte em menos de 24 horas. Em todas foram observadas elevada lotacao por area com escassa pastagem disponivel e grande quantidade de plantas arbustivas identificadas como C. intermedium e com sinais de terem sido consumidas pelos animais. Dois bovinos foram necropsiados e os achados mais importantes foram congestao de mucosas conjuntivais e vulvovestibular; hemorragias e evidenciacao do padrao lobular no figado; hemorragia, congestao e edema pulmonares; congestao esplenica e encefalica, alem de hemorragias multifocais no coracao. Amostras de tecidos desses bovinos foram avaliadas, com alteracoes histologicas importantes no figado, caracterizadas por necrose acentuada de hepatocitos e hemorragia, indicativas de hepatopatia toxica aguda e, no encefalo, foram observadas alteracoes astrocitarias em substância branca de cerebro e cerebelo e na substância cinzenta do cerebelo, caracterizadas por tumefacao celular com citoplasma amplo e eosinofilico, nucleo picnotico, ora excentrico. Essas alteracoes astrocitarias foram evidenciadas pela tecnica de imuno-histoquimica (IHQ), com imunomarcacao fortemente positiva para os anticorpos anti-proteina S100 (anti-S100) e anti-proteina glial fibrilar acida (anti-GFAP). O trabalho visa enfatizar em lesoes encefalicas relacionadas a hepatotoxicidade aguda em bovinos.

Caracterização imuno-histoquímica das alterações encefálicas em bovinos com hepatopatia tóxica por Senecio sp

Senecio spp. poisoning is an important cause of illness and death of cattle in Rio Grande do Sul, Brazil, and is often manifested by neurologic clinical signs and histological brain changes. Histological evaluation was performed on liver and brain samples of ten cattle naturally poisoned by Senecio sp. Samples of cerebrum, brainstem and cerebellum were stained with periodic acid-Schiff (PAS), and immunohistochemistry was carried out, employing anti-fibrillary acidic protein (GFAP), anti-S100 protein and anti-vimentin antibodies. The histological finding in the brain included mild to severe vacuolation in the white matter and the junction of gray and white matter, characterized as spongy degeneration. Histochemical and immunohistochemical staining revealed no significant findings compared with the brains of eleven adult cattle without liver and/or brain changes used as controls.

Avaliação lectino-histoquímica de fígado e rim de ovinos com fotossensibilização causada por Brachiaria decumbens

Inspite that Brachiaria spp. are most important forage grasses for beef cattle raising in Brazil, they can under certain conditions be toxic, cause outbreaks of hepatogenic photosensibilization and determine severe economic losses. Animals grazing toxic Brachiaria spp. commonly show in their liver foamy macrophages, isolated or grouped together, and crystals inside the biliary ducts. Steroidal saponins have been identified in these crystals and are liable for damage the liverleading to accumulation of phylloerytrin. Occasionally negative images of the crystals may be seen in the cytoplasm of foamy macrophages. The pathogenesis of formation and the type of material stored in the foamy cells is still unknown. The lectin histochemistry aims to assist in the detection of foamy macrophages and consequently in the diagnosis of the poisoning. Lectin histochemistry detects what kind of specific sugar residues exists in the cytoplasm of the foamy cells. The purpose of the present study was to identify the most suitable lectins the detection of steroidal saponins in the liver and kidney of sheep with photosensitization caused by Brachiara decumbens. Fragments of liver and kidney of fifteen sheep of both sexes and variable age, from Conceicao do Mato Dentro, Minas Gerais, southeastern Brazil, and one sheep kept free grazing Brachiaria spp. were evaluated by lectin histochemistry. Fourteen lectins were used (Con-A, DBA, SBA, PNA, SJA, RCA-I, UEA-I, WGA, SWGA, GSL, PSA, PHA-L, PHA-E and LCA). It was found that the PNA lectin detected in the liver of sheep with photosensitization, caused by ingestion of Brachiaria decumbens, showed specificity and great binding reactivity for foamy macrophages, and also specificity and slight binding reactivity for hepatocytes. The WGA lectin showed specificity and moderate binding reactivity for foamy macrophages of the liver, and also specificity and slight binding reactivity for hepatocytes. The SBA, GSL and LCA lectins showed specificity and moderate binding reactivity for foamy macrophages, but were not specific for hepatocytes. The PNA lectin showed greater binding reactivity in the kidney of the sheep. Lectin histochemistry evaluation had not yet been performed in liver and kidney of sheep with photosensitization caused by Brachiaria spp.