Angélica Terezinha Barth Wouters

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.

Treadmill Exercise Protects Against Pentylenetetrazol-Induced Seizures and Oxidative Stress after Traumatic Brain Injury

Traumatic brain injury (TBI) is a major cause of acquired epilepsy, and significant resources are required to develop a better understanding of the pathologic mechanism as targets for potential therapies. Thus, we decided to investigate whether physical exercise after fluid percussion injury (FPI) protects from oxidative and neurochemical alterations as well as from behavioral electroencephalographic (EEG) seizures induced by subeffective convulsive doses of pentylenetetrazol (PTZ; 35 mg/kg). Behavioral and EEG recordings revealed that treadmill physical training increased latency to first clonic and tonic-clonic seizures, attenuated the duration of generalized seizures, and protected against the increase of PTZ-induced Racine scale 5 weeks after neuronal injury. EEG recordings also revealed that physical exercise prevented PTZ-induced amplitude increase in TBI animals. Neurochemical analysis showed that exercise training increased glutathione/oxidized glutathione ratio and glutathione levels per se. Exercise training was also effective against alterations in the redox status, herein characterized by lipid peroxidation (thiobarbituric acid reactive substances), protein carbonyl increase, as well as the inhibition of superoxide dismutase and Na⁺,K⁺-ATPase activities after FPI. On the other hand, histologic analysis with hematoxylin and eosin revealed that FPI induced moderate neuronal damage in cerebral cortex 4 weeks after injury and that physical exercise did not protect against neuronal injury. These data suggest that the ability of physical exercise to reduce FPI-induced seizures is not related to its protection against neuronal damage; however, the effective protection of selected targets, such as Na⁺/K⁺-ATPase elicited by physical exercise, may represent a new line of treatment for post-traumatic seizure susceptibility.

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.

Acute and repeated-doses (28 days) toxicity study of Hypericum polyanthemum Klotzsch ex Reichardt (Guttiferare) in mice.

Hypericum polyanthemum, a South Brazilian species showed antidepressant-like and antinociceptive effects in rodents. Since limited information is available on the toxicity and safety profile of the Hypericum genus, we therefore investigated whether H. polyanthemum cyclo-hexane extract (POL) treatment could be associated with toxicity in preclinical setting using mice as an experimental model. These toxicity studies were based on the guidelines of the Organization for Economic Cooperation and Development (OECD-guidelines 423 and 407). Animals received POL single dose (2000 mg/kg, p.o.) or daily for 28-days (90, 450 and 900 mg/kg, p.o.). Acute toxicity study did not detect any clinical signs, changes in behavior or mortality. In repeated dose toxicity study, POL affected the body weight gain and induced biochemical, hematological and liver histological changes at 450 and 900 mg/kg. Mice treated with POL 90 mg/kg did not show any toxicity signs. In conclusion H. polyanthemum can be classified as safe (category 5) according to OECD acute toxicity parameters. However, the alterations observed after repeated treatment with high doses suggest that the liver could be the target organ on potential H. polyanthemum toxicity and point to the need of further toxicity studies.

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.

Aspectos clínicos e laboratoriais em ovinos submetidos a dietas com níveis elevados de enxofre com objetivo de indução de polioencefalomalácia

Polioencephalomalacia (PEM) is a neuropathologic condition of ruminants that can be induced by a variety of factors including excessive sulfur intake. This study aimed to investigate the relationship between diets rich in sulfur, high levels of ruminal hydrogen sulfide and the occurrence of polioencephalomalacia in sheep. Eighteen sheep were divided into three groups (G1, G2, and G3) and supplemented with 0.2%, 0.9% and 1.2% sulfur in the diet respectively. Clinical evaluation (i.e. heart rate, respiratory rate, rectal temperature and rumen motility) and laboratory exams (i.e. ruminal hydrogen sulfide concentration, venous gas analysis, ruminal pH, serum and liver copper concentration, computed axial tomography, necropsy, and histopathological examination) were performed. Rectal temperature, venous gas and ruminal pH were within normal limits. Tachycardia and tachypnea were observed in sheep of the three groups. Rumen motility was decreased in animals of group G2 and G3 when compared with G1. The higher the sulfur intake, the lower was the serum and liver levels of copper. Increased ruminal hydrogen sulfide concentration was detected in G2 and G3 sheep. None of the animals had clinical signs of PEM. Computed axial tomography, macroscopic and histopathological examination of the central nervous system showed no evidence of PEM. It is suggested that other factors are associated with excessive sulfur consumption for a PEM outbreak to occur in sheep.

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.

Canine papillomatosis: a retrospective study of 24 cases (2001-2011) and immunohistochemical characterization

Foi realizado um estudo retrospectivo de 24 casos de papilomas em caes diagnosticados no periodo de janeiro 2001 a marco de 2011, bem como a sua caracterizacao imuno-histoquimica (IHQ). Caes sem raca definida foram os mais afetados, a idade media foi de 3,1 anos, com variacao de 6 meses a 10 anos e nao houve predilecao sexual. Quanto a localizacao das lesoes, 75,0% estavam na pele, 16,7% no labio e 8,3% em palpebra. Na avaliacao histologica havia proliferacao papilar exofitica do epitelio escamoso em 87,5% e papilar endofitica (invertido) em 12,5%. O tumor era caracterizado por hiperplasia do estrato espinhoso (87,5%) com coilocitos (70,8%) e inclusoes intranucleares basofilicas palidas (8,3%); o estrato granular estava proeminente com grande quantidade de grânulos de querato-hialina (95,8%); e havia hiperqueratose do estrato corneo (100%). Na avaliacao IHQ para Papillomavirus houve marcacao nos estratos granuloso e corneo em 83,3%. Estes achados indicam que os papilomas em caes sao causados por Papillomavirus, as lesoes epiteliais sao decorrentes do efeito citopatico viral, as particulas virais estao no nucleo das celulas e corpusculos de inclusao sao raros.

Brain lesions associated with acute toxic hepatopathy in cattle

Samples of the liver, telencephalon, brainstem, and cerebellum were obtained from 22 bovids suffering from spontaneous or experimental acute toxic liver disease. Perreyia flavipes larvae, and leaves of Cestrum corymbosum, Cestrum intermedium, Dodonaea viscosa, Trema micrantha, and Xanthium cavanillesii were the causal agents in the disorders studied. Hematoxylin and eosin and periodic acid–Schiff staining, as well as anti-S100 protein (anti-S100), anti–glial fibrillary acidic protein (anti-GFAP), and anti-vimentin immunostaining were used to evaluate the brain sections. Astrocytic changes were observed in all samples and were characterized by swollen vesicular nuclei in gray (Alzheimer type II astrocytes) and white matter; and by abundant eosinophilic or vacuolated cytoplasm with pyknotic nuclei in the white matter. These changes were evidenced by anti-S100 and anti-GFAP immunostaining. Our study demonstrates major changes in astrocytes of cattle that died with neurologic clinical signs as the result of acute toxic liver disease.