Franklin Riet-Correa

Meningoencefalite em bovinos causada por herpesvírus bovino-5 no Mato Grosso do Sul e São Paulo

Fifteen outbreaks of bovine herpesvirus-type 5 (BHV-5) infection were diagnosed from August 1993 to December 1996. Fourteen outbreaks occurred in the State of Mato Grosso do Sul and one in the State of Sao Paulo. Cattle 6 to 60 months old were affected. Morbidity reached 0.05% to 5% and case fatality rate was nearly 100%. The disease occurred in different municipalities and at different times of the year. Clinical signs were exclusively nervous, and the clinical course varied from 1 to 15 days. The main histologic lesions were meningitis, diffuse encephalitis and necrosis of the cerebral cortex with intranuclear inclusion bodies in astrocytes and neurons. BHV-5 was isolated from 11 out of 12 brains of infected animals inoculated in calf testis cells and MDBK cells. The virus was identified by immunoperoxidase staining with use of monoclonal specific antibodies. Outbreaks of infection by BHV-5 represent 5% of the total number of bovine cases submitted for diagnosis to the Clinical Hospital of the University of Mato Grosso do Sul. These results indicate the importance of the disease in Mato Grosso do Sul and the need for its differentiation from other diseases which affect the nervous system.

Intoxicações por plantas em ruminantes no Brasil e no Uruguai: importância econômica, controle e riscos para a saúde pública

As intoxicacoes por plantas em animais de producao, no Brasil e no Uruguai sao conhecidas desde que os pioneiros Espanhois e Portugueses introduziram as primeiras cabecas de gado em pastagens naturais da regiao. As perdas economicas ocasionadas pelas intoxicacoes por plantas podem ser definidas como diretas ou indiretas. As perdas diretas sao causadas pelas mortes de animais, diminuicao dos indices reprodutivos (abortos, infertilidade, malformacoes), reducao da produtividade nos animais sobreviventes e outras alteracoes devidas a doencas transitorias, enfermidades subclinicas com diminuicao da producao de leite, carne ou la, e aumento a susceptibilidade a outras doencas devido a depressao imunologica. As perdas indiretas incluem os custos de controlar as plantas toxicas nas pastagens, as medidas de manejo para evitar as intoxicacoes como a utilizacao de cercas e o pastoreio alternativo, a reducao do valor da forragem devido ao atraso na sua utilizacao, a reducao do valor da terra, a compra de gado para substituir os animais mortos, e os gastos associados ao diagnostico das intoxicacoes e ao tratamento dos animais afetados (Riet-Correa et al. 1993, James 1994). As perdas economicas causadas pelas intoxicacoes por plantas sao dificeis de se estimar por que nao existem dados confiaveis sobre todos esses componentes, no entanto, as perdas causadas por mortes sao faceis de determinar quando dispomos de dados elaborados por laboratorios de diagnostico, sobre a frequencia das causas de mortes dos animais numa determinada regiao.

Polioencefalomalacia em bovinos nos estados de Mato Grosso do Sul e Säo Paulo

Thirty outbreaks of polioencephalomalacia (PEM) were diagnosed from August 1993 to October 1997. Twenty nine occurred in the state of Mato Grosso do Sul and one in Sao Paulo. The disease affected cattle from 4 months to 7 years of age. Morbidity rates ranged from 0.02% to 14.28% and case fatalities from 42.5 % to 100%. The disease was not seasonal. All outbreaks occurred in cattle grazing Brachiaria spp, except one affecting feedlot cattle. Only neurologic signs were observed, and the course of the disease varied from 12 hours to 4 days in untreated cattle. Most animals treated with thiamine and dexamethazone recovered. Moderate cerebral edema was observed at necropsy. Cell changes were characterized by laminar necrosis and gitter cells. In two cases moderate cortical and submeningeal hemorrhages were observed. Nine cases had perivascular and submeningeal infiltrations by eosinophils. Sodium ion concentration of the cerebrospinal fluid was elevated in one case. The cause of PEM in the region was not determined, but the results suggest that in some cases sodium chloride intoxication/water deprivation could play a role in the etiology of the disease. PEM represents 4.78% of cattle disease diagnosed at the Pathology Laboratory of the Federal University of Mato Grosso do Sul.

Enfermidades do sistema nervoso dos ruminantes no sul do Rio Grande do Sul

The main epidemiological, clinical and pathologic aspects of the diseases of the nervous system in cattle in Southern Rio Grande do Sul are described, including, the following conditions: cerebellar abiotrophy; cerebellar hypoplasia; congenital hypermetria; arthrogryposis; congenital hypomyelinogenesis; brain abscess; listeriose; tetanus; botulism; focal symmetrical encephalomalacia; rabies; leucosis; encephalitis by Herpesvirus Bovine-5; bovino malignant catarrh; intoxications by Solanum fastigiatum, Claviceps paspali, Halimium brasiliense, Diplodia maydis, and Ramaria flavo-brunnescens; hepatoencephalopaty caused by Senecio spp. and Echium plantagineum; ketosis; coenurosis; and spinal syndrome.

Viroses confundíveis com febre aftosa

Diseases to be considered in the differential diagnosis of foot-and-mouth disease are reviewed. The main aspects relating to the diagnosis of vesicular stomatitis, bovine virus diarrhea, malignant catarrhal fever, bovine herpesvirus 1 and 5, andem ulcerative stomatitis associated with bovine parvovirus are described. Bluetongue, that probably occurs in Rio Grande do Sul because antibodies to the virus have been detected in cattle and sheep; is refered. Bovine ulcerative mammilitis, reported in other Brazilian States, rinderpest, reported and eradicated in the State of Sao Paulo in 1921, and popular stomatitis are also cited, and so are two exotic diseases: vesicular exanthema and swine vesicular disease.

Estudos histomorfométrico e histológico das lesões ósseas causadas por flúor em aves

Sodium fluoride was administered in the water to 2 groups of 25 Shaver female poultry. Group A received fluoride from 1 to 120 days of age and group B from 61 to 120 days. Each group was divided into 5 treatments, with 5 chickens each, which received 0, 25, 50, 200, and 400 ppm of fluoride in the water, respectively. All animals were killed at 120 days of age. For histomorphometric studies the left femur and tibia were used, and for histologic studies the right femur and tibia. In the cortical bone, cortical porosity was slightly increased by fluoride, but the differences with the control group were not significant. Cortical thickness increased in the animals treated with fluoride (p<0,05, r2 = 0,59 ). In the trabecular bone, of group A, trabecular thickness (TT) (p<0,05, r2 = 0,63) and trabecular bone volume (TBV) (p<0,05, r2 = 0,72) increased in treatments receiving 25-200 ppm, and decreased in the 400 ppm treatment, as it was demonstrated by quadratic regression analysis. In group B there was a positive linear correlation on TT (p<0,05, r2 = 0,98) and TBV (p<0,05, r2 = 0,77) with fluoride ingestion.The osteoid surface was also positively correlated with the amount of fluoride ingested by the animals (p<0,001, r2 = 0,80). These results suggest that fluoride improves osteoblastic function resulting in increased osteoid production and bone apposition. In the other hand, in the animals treated with 400 ppm of fluoride for 120 days bone apposition was reduced suggesting a functional alteration of the osteoblasts or improved bone resorption. In the histological study of bone tissue all animals that received fluoride showed an increased trabecular thickness which was more marked in the 200-400 ppm treatments. In chickens treated with 200-400 ppm of fluoride osteoblasts and osteoclasts were more numerous suggesting an increased bone turnover. In cortical bone Haversian canals were narrowed on the periosteal surfaces and resorption spaces were enlarged on the endosteal surfaces.

HIPOPLASIA CEREBELAR E PORENCEFALIA EM BOVINOS CHAROLÊS NO SUL DO RIO GRANDE DO SUL

Two cases of cerebellar hypoplasia in Charolais calves from a herd of a farm located in the municipality of Capao do Leao, Southern Brazil are described. One calf with cerebellar clinical signs at birth, showed incoordination, hypermetria and intention tremors, mainly in the neck and head. The other calf was recumbent with opisthotonos. The gross lesions were characterized by cerebellar hypoplasia, with only remnants of cerebellar floculus and parafloculus and an expanded fluid-filled space covered by leptomeninges. Mild hydrocephalus and porencephaly were observed in the cerebrum. It was discussed the possible etiologies and suggested the possibility of the disease has been caused by bovine viral diarrhea-mucosal disease (BVD-MD) virus despite of negative results of imuno-histochemical technique for detection of this virus in cerebellar fragments of the affected calves.

Isolamento de Arcanobacterium pyogenes de granuloma actinomicóide em bovino

A round hard lesion measuring 12x11x7cm, with a presumptive diagnosis of lechiguana, was observed in the submandibular region of a cow. Bacteriologic and histologic examinations from biopsies from the lesion were not conclusive. The intradermic test for tuberculosis was negative. The immunodiffusion serologic test to detect antibodies against Pasteurella granulomatis was negative. The animal was killed and necropsied. The submandibular lesion consisted in a hard whitish tissue with yellowish granules measuring up to 3mm scattered within it. A fibrous capsule was surrounding the lesion. Histologically, the lesion was characterized by multifocal piogranulomas with rosetes made up of bacterial colonies in their center, surrounded by Splendore-Hoeppli reaction and neutrophils at the periphery. Epithelioids cells, and fibrous tissue infiltrated by lymphocytes were observed around those lesions. Arcanobacterium pyogenes in pure culture was isolated from samples obtained at necropsy. It is concluded that A. pyogenes could be involved in actinomycotic-like lesion with clinical and pathological aspects similar to lechiguana, tuberculosis and actinobacilosis.

Histological changes caused by experimental Riedeliella graciliflora (Leg. Papilionoideae) poisoning in cattle and laboratory animals

Tissues from cattle, mice, rats and guinea pigs experimentally intoxicated by Riedeliella graciliflora were studied histologically. Cattle lymph nodes, spleen, Peyer patches and peribronchial lymphoid tissues had diffuse necrosis of lymphocytes, mainly in the germinal centers of the follicles. This lesion was less severe in laboratory animals. All species had severe enteritis with infiltration of the lamina propria by mononuclear cells. Some cells in this infiltrate were necrotic. Degeneration and necrosis of the epithelial cells, mainly in the tip of the villi, and detachment of the epithelial lining from the lamina propria were also observed. In the liver the trabecular structure was disrupted and the hepatocytes had some degree of individual necrosis and degeneration. A tubular nephrosis was observed in the kidneys. Liver, lung, kidney, intestine and lymph nodes had different degrees of congestion. Those lesions are similar than those caused by Polygala klotzschii, a plant that contains 5-metoxi-podophyllotoxin.

Fotossensibilização hepatógena em bovinos no sul do Rio Grande do Sul

The epidemiological and pathological aspects of 19 outbreaks of photosensitization in cattle, observed in southern Brazil, between 1984 e 1997 were studied. The disease occurs mainly in spring and fall with morbidity of 0.08% to 64% and mortality of 0 to 14%. Cattle of all ages are affected. The pastures on which outbreaks occur are characterized by low, flat and wet land, used alternatedly for rice or other crops and natural or cultured pastures of clover, oat and ryegrass. The disease is characterized clinically by depression, anorexia, salivation and photosensitization of white or slightly colored and hairless skin such as muzzle, nostrils, eyelids, udder, groin and vulva. In severe cases the skin, mainly of dorsal midline and legs, was thickened, necrotic and sloughed revealing a raw area of subcutaneous tissue. The macroscopic lesions were tipically related to hepatic insuficiency. Jaundice, yellow to orange discoloration and swelling of the liver, edema of the gall bladder, excess of serous fluid in body cavities and occasionally subcutaneous and peritoneal edema were observed. The histological changes are characterized by degenerative changes of hepatocytes that are diffusely or zonal vacuolated and swollen. Individual or ramdomly scattered foci of hepatocellular necrosis, bile ductular proliferation, and portal fibrosis were also observed. The disease was characterized as a bovine hepatogenous photosensitivity syndrome resulting from primary damage to the liver parenchyma. The etiology is unknown and the main known causes of hepatogenous photosensitivity in cattle were ruled out.