Neospora caninum is a protozoan which can cause abortions in caprines. However, information regarding the humoral immune response and the occurrence of reproductive disorders is scarce. This is the first study in which the kinetics of antibodies is studied in pregnant goats naturally infected by N. caninum, as well as their respective conceptuses. The subclasses of IgG (IgG1 and IgG2) were also evaluated in pregnant goats. Reproductive problems related to neosporosis (abortion and stillbirth) occurred in 15.38% of the goats. There was a statistically significant association between the increased titres of maternal IgG in the second half of the gestational period with the occurrence of endogenous transplacental transmission. The rate of congenital transmission was 77%. During the gestational period of the seropositive goats, there was mainly a predominance of the subclass IgG2, although mixed patterns of IgG2-IgG1 and the IgG1 pattern were also observed. These results indicate that N. caninum is responsible for the occurrence of important alterations in the humoral immune response of naturally infected goats, and is also a potential causative agent for reproductive disorders in goats. The high proportion of infected conceptuses reinforces the suggestion that congenital infection is one of the main routes of parasite transmission in goats.

This study was conducted to determine the seroprevalence of anti-Neospora caninum antibodies and to investigate the risk factors related to seroprevalence in dogs from urban and rural areas with distinct economic activities (milk and coffee production) in Minas Gerais state, Brazil. For this purpose, blood samples from 703 dogs were collected and questionnaires addressing epidemiological aspects were completed by dog-owners. The sera were analysed for anti-N. caninum antibodies by indirect fluorescent antibody tests (IFAT ≥ 1:50). Association between epidemiological aspects and seropositivity in dogs was evaluated with multivariate logistic regression models. A total of 80 (11·4%) dogs tested positive for N. caninum. In the multivariate logistic regression models, dogs aged >4 years, dogs used as guard dogs, dogs that spontaneously hunt, and history of bovine abortion were found to be greater risk factors for canine N. caninum infection. When we considered only dogs from rural areas, an association with seroprevalence was seen for milk farms, dogs not fed with commercial food, dogs that hunt, and dogs used as guard dogs.

Este estudo teve como objetivo determinar a prevalência e achados anatomopatológicos de tumores primários e metastáticos do coração ou de tecidos da base do coração, diagnosticados em caninos do Sul de Minas Gerais. O diagnóstico foi realizado mediante análise histopatológica e imuno-histoquímica das neoplasias. Durante os anos de 1994-2009, foram realizadas 2397 necropsias em caninos. Neoplasias no coração foram detectadas em 31 cães (1,29%), onde, sete (22,58%) eram primárias e 24 (77,42%) metastáticas. As neoplasias diagnosticadas como primárias do coração foram o hemangiossarcoma (1/7) e o mixoma (1/7); e como primárias da base do coração o quimiodectoma (3/7) e o carcinoma de tireoide ectópica (2/7). A frequência foi maior em cães machos (5/7), da raça Boxer (3/7) e com idade média de 9,7±1,88 anos. Nas neoplasias metastáticas, a frequência foi maior em fêmeas (15/24), em cães da raça Rottweiler (7/24) e a idade média foi de 7,5±3,23 anos, sendo o linfoma de células T a neoplasia metastática de maior ocorrência (7/27).

Um surto de compactação primária de abomaso associada ao consumo de silagem de girassol ocorreu num rebanho bovino leiteiro do estado de Minas Gerais, do qual seis de 21 vacas secas em fase final de gestação e que recebiam silagem de girassol morreram. Os bovinos que adoeceram apresentaram distensão abdominal, fezes ressecadas e escassas e, nos bovinos que morreram, eram pastosas, escuras e fétidas; nesses havia também desidratação acentuada e palidez de mucosas. Três bovinos foram necropsiados e os achados patológicos eram constituídos principalmente por distensão acentuada do abomaso associada a grande quantidade de conteúdo alimentar ressecado coberto por coágulos de sangue. No abomaso havia úlceras, com perfuração da parede em um dos bovinos. A alimentação de bovinos de maior exigência nutricional com silagem de girassol de características indesejáveis como única fonte de volumoso foi o principal fator para a compactação de abomaso nos casos apresentados.

Neospora caninum has been described as a parasite that sporadically causes reproductive problems in goats. Several aspects of the pathogenesis of neosporosis in naturally infected goats remain to be established. The aims of the present study were to characterize the placental lesions in goats naturally infected by N. caninum and to evaluate several diagnostic techniques for effective detection of this protozoan in the goat placenta. Some placentas in this study originated from abortion and stillbirth in which there were severe lesions. The lesions were characterized mainly by necrosis involving the mesenchyme of the chorionic villi and trophoblast cells often alongside mononuclear inflammation and in some cases with neutrophilic infiltration. N. caninum DNA was detected in these placentas, but parasite structures were not visualized through immunohistochemistry (IHC). However, five of 11 placentas from N. caninum-infected goats that gave birth to healthy kids had histological lesions characterized by mononuclear inflammation. Of these 11 placentas, N. caninum DNA was detected in seven, and N. caninum tachyzoites were detected in only one of these seven placentas using IHC. The present study demonstrates that severe lesions in the placenta are associated with abortion and stillbirth in caprine neosporosis and the placental alterations are likely involved in abortion pathogenesis. Moreover, the results highlight the importance of using more than one diagnostic technique for the detection of the protozoan in placentas because N. caninum cannot be reliably detected by histological and immunohistochemical tests.

We performed a histopathological and immunohistochemical study of tissues outside the central nervous system in 48 cases of bovine rabies confirmed by direct immunofluorescence and/or immunohistochemistry (IHC) of the central nervous system. In the bovines of this study, mononuclear inflammation in all ganglia (trigeminal, spinal, stellate, and celiac) and adrenal medulla was observed. This injury also occurred in 85 % of neuro-pituitaries in 55 % of pars intermediate and 15 % of the pars distalis of pituitary evaluated. IHC was positive in 92.31 % of lumbar spinal ganglia, 90.9 % of trigeminal ganglia, stellate ganglia of 41.67 and 16.67 % of the celiac ganglia. One of the evaluated adrenal (1/17) showed strong immunohistochemical labeling in the cytoplasm of pheochromocytes. The pituitary IHC was positive in one case in the neurohypophysis (1/20) and in one case in the pars intermedia of the adenohypophysis (1/20). Data from this study indicate that in suspected cases of rabies, besides the complex pituitary rete mirabile and trigeminal ganglion, the evaluation of other ganglia, particularly the lumbar spinal, and adrenal may also contribute to the diagnosis and understanding of the clinical presentation and pathogenesis of the disease in bovines.

Abstract:Objectives: To investigate the effects of physical training on the liver morphology and morphometry after chronic use of alcohol in rats. Methods: Twenty-four Wistar rats were housed in cages with controlled environment and randomly divided into four groups according to treatment received. In the initial treatment, alcohol was administered to SA (sedentary alcohol) and EA (exercise alcohol) groups. After four weeks, physical training program was held on a treadmill with EA and EC (exercise control) groups. Area, perimeter, maximum and minimum diameter and form factor of nucleus and cytoplasm of hepatocytes were analyzed. Key findings: Micro-vesicular fatty degeneration, predominantly pericentrolobular, of mild to moderate intensity, was found especially in animals treated with alcohol. EC group showed nucleus area greater than the nucleus area of EA and SA groups. The form factor was lower in the EC group than in the EA group. EA group showed maximum cytoplasm diameter is smaller than in SC (sedentary control) group. Conclusions: Physical training for two weeks was not enough to suppress histopathologic changes in the liver caused by chronic use of alcohol in rats. Chronic use of alcohol seems to have minimized the beneficial effect of physical training in the nucleus area of hepatocytes.

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