Letícia Fiss

Evolução e reversibilidade das lesões neurológicas e cardíacas em ovinos intoxicados experimentalmente por Ateleia glazioviana e Tetrapterys multiglandulosa

To determine the reversibility of neurological and cardiac lesions in Ateleia glazioviana and Tetrapterys multiglandulosa poisoning, 3 groups of four sheep each were fed orally with the plants. In Group 1, 2 and 3, when sheep with nervous signs showed considerable increase of symptoms and risk of death, the plant administration was suspended. Group 4 with two sheep was used as control. Sheep from Group 1, fed 10g/kg during 6 days of fresh A. glazioviana collected in autumn were euthanized 8, 11, 16, and 21 days after the start of the experiment; they had shown regression of nervous signs, but had progressive cardiac lesions. Sheep from Group 2, fed during 8 days the same dose of fresh A. glazioviana collected in spring, were euthanized on days 9, 23, 38 and 68; they had shown regression of nervous signs and had no cardiac lesions. This suggests that the plant is less toxic in spring. Sheep from Group 3, fed 10g/kg during 11 days dry and ground T. multiglandulosa mixed with concentrated food, were euthanized on days 33, 33, 92 and 92; they had shown regression of nervous signs, and cardiac lesions were less severe on day 33 than on day 92. These results indicate that nervous lesions are reversible after the end of feeding, but cardiac lesions are progressive after discontinuation of the plant administration; these can be afterwards reversible if the animals do not anymore show clinical signs or die as a consequence of the poisoning. Results of those and previous experiments show that lesions of the nervous system are induced by lower doses than cardiac lesions and occur within a shorter period, what suggests that in spontaneous cases cardiac signs are always preceded by nervous signs, and that nervous signs can occur in the absence of cardiac lesions.

Senecio madagascariensis Poir. (Asteraceae): uma nova causa de seneciose em bovinos no Sul do Rio Grande do Sul

Two outbreaks of Senecio madagascariensis poisoning in cattle occurred in October 2013 in southern Brazil. Morbidity rate ranged were 3.2% and 6.1%, and lethality rate was 100%. A third case of poisoning occurred on a property in which out of 54 cattle one died with clinical signs of intoxication. In all cases, the cattle were in areas highly infested by S. madagascariensis that was in bloom. The clinical signs were diarrhea, tenesmus, opisthotonus, and progressive weight loss. Death occurred between 10 and 15 days after the onset of clinical signs. At necropsy, lesions were edema in the mesentery, in the wall of the rumen and abomasum, and in the walls of the gall bladder; the liver was firm with marbled aspect. Histologically, the liver had proliferation of fibrous connective tissue, especially in portal areas, hepatomegalocytosis, and bile duct hyperplasia. The observation of large number of S. madagascariensis in several farms in the counties of Arroio Grande, Pedro Osorio and Capao do Leao reinforces that this plant is in the process of adaptation and dissemination in this region and that other outbreaks may occur in coming years. The cases reported here apparently resulted from the consumption of the plant during the fall/winter of 2013, when it was in bloom. The quantification of alkaloids in S. madagascariensis revealed the presence of 500µg/g and 4000µg/g of pyrrolizidine alkaloids in the dry plant from two properties. It is believed that the large amount of the plant in the areas where the animals were and the amount of pyrrolizidine alkaloids found were factors that contributed to the occurrence of outbreaks.

Fasciolose aguda em bovinos no Sul do Brasil

Descrevem-se os aspectos epidemiologicos e patologicos de um surto de fasciolose aguda diagnosticado em bovinos na regiao sul do Rio Grande do Sul. De um lote de 70 vacas de tres anos de idade 15 apresentaram perda de peso 30-40 dias antes da paricao. Dessas, 10 vacas abortaram e 5 morreram. Os sinais clinicos caracterizaram-se por diarreia, fraqueza, anemia discreta e ictericia. Na necropsia havia liquido escuro na cavidade abdominal. Na cavidade toracica havia fibrina e coagulos de sangue aderidos ao pericardio e pulmoes, principalmente nos lobos diafragmaticos. O figado estava aumentado de tamanho e a superficie capsular estava irregular com areas claras e petequias. A superficie de corte estava irregular, firme e edematosa e podiam ser observadas estrias hemorragicas atraves do parenquima. Areas de fibrose e trombos esbranquicados ocluindo vasos sanguineos foram, tambem, observados. Os figados das 10 vacas que nao morreram foram condenados no abate por lesoes de fasciolose similares as observadas na necropsia. Microscopicamente, o figado apresentava areas de necrose de coagulacao, focos de hemorragia acentuada e desorganizacao do parenquima com acentuada infiltracao de neutrofilos e eosinofilos. Havia, ainda, fibrose e hiperplasia de celulas de ductos biliares. Formas imaturas de Fasciola hepatica foram observadas no parenquima rodeadas por hepatocitos em degeneracao, neutrofilos e eosinofilos, e hemorragia. O surto ocorreu em uma propriedade localizada em uma area endemica para a fasciolose, embora a forma aguda da enfermidade nao seja frequente em bovinos nesta regiao. E provavel que as vacas tenham se infectado pelas metacercarias liberadas do hospedeiro intermediario no final do outono ou no inicio da primavera na resteva de arroz onde foram colocadas antes da paricao. Embora mortalidade em bovinos devido a fasciolose seja infrequente, surtos podem ocorrer e a utilizacao de fasciolicidas eficientes para controlar as formas imaturas ou adultas deste parasita devem ser administradas aos bovinos para evitar eventuais perdas economicas.

Surto de criptosporidiose em bezerros no Sul do Rio Grande do Sul

This paper describes the epidemiology, clinical signs and pathology of an outbreak of cryptosporidiosis in calves in Southern Brazil. Thirty-five out of 400 calves with 30-45 days of age were affected and 16 died. The calves were born weak and just after birth they had yellow diarrhea, weight loss, dehydration, depression, and death between 10 and 15 days after onset of clinical signs. Congestion of the bowel and mesenteric blood vessels were observed at necropsy. Intestinal distension by gas and dilation of lymphatic vessels were also observed. Microscopically, the intestine showed flattening of the villi with necrosis and atrophy. Adhered to the surface of the villus epithelial cells there were round basophilic structures of 2- to 5-μm-diameter compatible with Cryptosporidium spp. Electron microscopy revealed the presence of different stages of the agent adhered to the microvilli of enterocytes. We alert the importance of cryptosporidiosis as a primary agent of diarrhea in calves. Preventive measures to reduce economic losses, environmental contamination, and also decrease of risk for public health are necessary.

Congenital hydranencephaly and cerebellar hypoplasia in water buffalo in southern Brazil.

Seven cases of hydranencephaly and cerebellar hypoplasia in a water buffalo herd are described. The herd of 133 females was divided for mating into 4 groups and mated with different bulls. The disease was observed in the offspring of 5 cows from only 1 group over a period of 6 years. These cows had all mated with the same bull during that period. All affected calves were unable to suckle, showed intention tremors, involuntary movements of the ears, depression, and blindness. Some calves were recumbent and others showed wide-based stance and inability to walk. At necropsy, all affected calves had similar lesions consisting of hydranencephaly and cerebellar hypoplasia. Histologically, the cavities were surrounded by normal-looking nervous tissue. The occurrence of the disease in the offspring of only 1 out of 6 bulls in different years, the similar lesions in all 7 calves affected, and the negative serology and immunohistochemistry for Bovine virus diarrhea virus and Bluetongue virus highly suggest that the disease is hereditary.

Paratuberculose em bovinos de corte na região Sul do Rio Grande do Sul

The epidemiological, clinical and pathological aspects of paratuberculosis diagnosed in southern Rio Grande do Sul in a beef cattle property are described. Two cattle raised extensively and that presented progressive weight loss and chronic diarrhea were necropsied. The mesenteric lymph nodes were enlarged and edematous. The intestinal mucosa was thickened and wrinkled with cerebroid aspect, especially in the final portion of the ileum, ileocecal valve and cecum. Fragments of the organs were fixed in 10% formalin, embedded in paraffin, sectioned and stained with hematoxylin and eosin (HE) and Ziehl-Neelsen (ZN). Feces samples were referred to Departamento de Medicina Veterinaria, Area de Medicina Veterinaria Preventiva da Universidade Federal Rural de Pernambuco, for the cultivation of Mycobacterium avium subsp. paratuberculosis with Lowenstein Jensen for mycobacterial and PCR analysis. Histologically, granulomatous enteritis was observed in the jejunum, ileum, cecum and rectum, and in multifocal areas the duodenum and colon. Lymphangitis and granulomatous adenitis was also observed. In ZN staining numerous resistant acid-fast bacilli (AFB) within macrophages, giant cells of Langhans and mesenteric lymph nodes in the jejunum, ileum cecum and rectum were observed. There was no bacterial growth in stool samples. Five samples amplified the gene sequence IS900 specific for Mycobacterium aviumsubsp. paratuberculosis. It can be concluded that paratuberculosis, despite the few reports, occurs in beef cattle raised extensively in southern Rio Grande do Sul, Paratuberculosis may have a higher prevalence in the region than it is assumed. There is need for diagnosis of this disease and to assume effective measures for its control, as for many it is still considered an exotic malady in Brazil.

Intoxicação espontânea por Amaranthus hybridus (Amaranthaceae) em bovinos no sul do Rio Grande do Sul

An outbreak of Amaranthus hybridus poisoning in cattle was observed in February/March 2013 in southern Rio Grande do Sul, Brazil. The morbidity rate observed was 48.33%, the mortality rate was 41.66% and lethality rate was 86.20%. The diagnosis of A. hybridus poisoning was made based on the epidemiological data, clinical signs, macroscopic and histological lesions characteristic of intoxication by nephrotoxic plants and by the presence of large amounts of the plant in the area where cattle were placed. Invasion of Brachiaria sp. pasture by A. hybridus alerts for the possibility of the occurrence of poisoning not only in stubble areas with lack of forage. In the case reported here there was abundant forage availability in the area where the outbreak occurred. Favorable climatic conditions and fertile soil for planting pasture, probably favored the growth of this invasive species.