Aborto em bovinos e bubalinos: causas específicas e inespecíficas / Abortion in cattle and buffaloes: specific and non-specific causes

O aborto é caracterizado como a expulsão do feto sem viabilidade para fora do ambiente uterino da progenitora durante o período que vai do 42° dia a o 260° dia. São descritos diversos fatores infecciosos e não infecciosos como etiologia para o aborto. Dentre os infecciosos, destacam-se as infecções por bactérias, vírus, protozoários e fungos. Enquanto as causas não infecciosas englobam falhas de manejo nutricional, intoxicações e medicamentos que ocasionalmente podem levar à morte fetal. Essa mortalidade fetal é causa importante de perdas reprodutivas na cadeia produtiva de animais domésticos, especialmente bovinos e bubalinos. Ambas as espécies participam da produtividade econômica no Brasil e compartilham de diversas doenças que são causas de aborto. Nesse contexto, o objetivo desta revisão foi reunir e discorrer sobre as principais informações concernentes às possíveis etiologias do aborto, sejam elas de origem infecciosa ou não infecciosas nas espécies bovinas e bubalinas no Brasil.

Abortion is characterized as the expulsion of the non-viable fetus outside the mother's uterine environment during the period between the 42nd day to the 260th day. Several infectious and non-infectious factors are described as etiology for miscarriage. Among the infectious, infections by bacteria, viruses, protozoa, and fungi stand out, while non-infectious causes include failures in nutritional management, poisoning, and medications that occasionally can lead to fetal death. This fetal mortality is an important cause of reproductive losses in the production chain of domestic animals, especially cattle and buffaloes. Both species participate in economic productivity in Brazil and share several diseases that are causes of abortion. In this context, this review aimed to gather and discuss the main information concerning the possible etiologies of abortion, whether of infectious or non-infectious origin in bovine and buffalo species in Brazil.

Leptospirosis in dairy cattle from southern Brazil - risk factors

Background: Cattle are susceptible to chronic leptospirosis infection, that results in reduced milk production and reproductive disorders such as abortions, stillbirths, fetal malformation, and mummified fetuses, causing significant economic losses.Commercially available vaccines against leptospirosis offer limited protection to cattle because they contain only the mostprevalent serovars worldwide, even though they are not prevalent in the specific region. This study aimed to evaluate theprevalence of specific antibodies against Leptospira serogroups, reproductive disorders and the risk factors in dairy herdsfrom different mesoregions of Rio Grande do Sul State, Southern Brazil.Materials, Methods & Results: An epidemiological survey was conducted, and serum samples from the bovine population representative of three mesoregions (MR1, MR2, and MR3) were studied; the samples were collected and tested forleptospirosis using the microscopic agglutination test (MAT) for 12 serogroups checking for the presence of agglutination.A total of 442 blood samples were collected from dairy cattle from November to December 2019 (MR1, 187; MR2, 88;and MR3, 167), including cows vaccinated with different commercial vaccines during the three months before sample collection (n = 295) and non-vaccinated against leptospirosis (n = 147). At the time of collection, an interview was conductedwith the owners with questions about the health of the animals, management, habitat, feeding and reproduction. Chi-squaretests univariate analysis with the SPSS® version 20.0 were performed to estimate the association of serogroup Djasimanseroreactivity with the occurrence of reproductive problems and related risk factors. The mean prevalence of antibodiesagainst leptospires was 78.7% (MR1, 74.9 %; MR2, 84.1 %; and MR3, 80.2 %). Serogroup prevalence was different in...

Abortamento por Neospora caninum em bovinos de leite no sul de Santa Catarina, Brasil / Abortion due to Neospora caninum in dairy cattle in Southern Santa Catarina state, Brazil

Background: Neosporosis is a cosmopolitan disease known as the main infectious cause of abortion in cattle, reported in several states in Brazil. The transplacental transmission in cattle is responsible for perpetuating the disease in the herd. In the state of Santa Catarina, previous studies on this protozoan in cattle are mostly serological surveys. To increase information about this reproductive disorder, this work describes the diagnosis of abortions due to Neospora caninum in dairy cattle from state of Santa Catarina and the follow-up for 4 years in a farm affected by neosporosis. Cases: From 2015 to 2019, necropsy was performed on 10 aborted bovine fetuses, between fifth and eighth month of pregnancy, with 1 fetus aborted in 2015, 3 in 2016, 2 in 2017 and, 4 in 2019, all originating from the same dairy property in the southern region of state of Santa Catarina. No macroscopic lesions were found. Histopathology revealed mild to moderate multifocal mononuclear necrotizing encephalitis in 5 fetuses, and multifocal mild mononuclear myositis and myocarditis in 4 and 3 fetuses, respectively. Polymerase Chain Reaction (PCR) using primers based on the Nc-5 gene was positive for N. caninum in five fetuses. Three visits were performed in the farm for epidemiological evaluation and blood samples collection for IgG antibodies anti-N. caninum (IFAT). The total herd was 170 Jersey, Holstein and crossbred cattle, raised in a semi-confined system with mechanical milking system. Since 2014, there has been a significant increase in abortions cases, approximately 20 cows had abortions; in the year 2015, approximately 10; in 2016, less than 5; in 2017, 4 cows aborted; in 2018, 11 abortions and, in 2019, there were 4 abortions. An increase in the rate of return to estrus was also reported, and both primiparous and multiparous cows had reproductive disorders. Abortions were recorded throughout the year and occurred predominantly between the fourth and sixth month of pregnancy. In 2016, an Indirect Immunofluorescence Reaction (IFAT) was performed on sera from 26 cows (13 with a history of reproductive disorders and another 13 without disorders). Of these, 50.0% (13/26) were seropositive, with titers ranging from 100 to 1600 (cutoff ≥100). The Enzyme Immunoassay (ELISA) of the entire herd was carried out in 2017, with 26.54% (43/162) of seropositivity, 8.02% (13/162) suspect, and 30.4% (17/56) had reproductive disorders. It was observed that only animals born on the property were used for replacement, there was less possibility of direct contact between dogs on the property with milking facilities, placental and fetal remains, properly disposing of these, incinerating or burying. Thirty animals were discarded from the property, 25 of which had reproductive disorders. All young female daughters of seropositive cows remained on the property for replacement. During the evaluation period, all dogs were eliminated. Discussion: In this study, the diagnosis of neosporosis was made through epidemiology, histopathological lesions characterized by mononuclear encephalitis, myocarditis and myositis, and detection of the agent by PCR, associated with serological techniques. The lesions observed are indicative of N. caninum infection and are compatible with lesions observed in other studies. Serological screening is important to complement the diagnosis of abortion by N. caninum and to help control the agent in herds. From this report it is concluded that N. caninum is an important agent of reproductive disorders in cattle in the southern region of Santa Catarina, the different serological analyzes showed a good screening index for the inclusion of control strategies. In addition, the monitoring of reproductive rates of affected properties becomes necessary over the years, allowing better observation of control strategies.

Necrotizing placentitis in a cow caused by Bacillus cereus / Placentite necrotizante em uma vaca por Bacillus cereus

This report described a case of necrotizing placentitis caused by Bacillus cereus in a cow associated with abortion and maternal lethality. The etiological diagnosis of placentitis by B. cereus was based on histopathology of placenta, cytology and bacterial isolation from intrauterine aminiotic fluid in retained placenta and further characterization of the pathogen by the MALDI-TOF. Although, B. cereus abortions are sporadic, the bacterium has the ability to release necrotizing toxins that can lead to placentitis, fetal death and abortion.(AU)

Este relato descreve a placentite necrotizante causada por Bacillus cereus em uma vaca associada a aborto e mortalidade materna. O diagnóstico etiológico de placentite por B. cereus foi baseado na histopatologia da placenta, citologia e isolamento bacteriano partir do líquido aminiótico em placenta retida e identificação do patógeno pela técnica de MALDI-TOF. Embora abortos por B. cereus sejam esporádicos, a bactéria tem a capacidade de liberar toxinas necrotizantes que podem levar a placentite e aborto.(AU)

Risk factor analysis associated with Neospora caninum in dairy cattle in Western Brazilian Amazon / Análises de fatores de risco associado a Neospora caninum em gado leiteiro na Amazônia Ocidental Brasileira

Neospora caninum is considered to be one of the main causes of abortion among cattle. The present survey was conducted in the municipality of Rolim de Moura, Rondônia State, Brazil. A questionnaire that investigates the epidemiological aspects of neosporosis was used in the analysis of risk factors associated with the animal-level and herd-level prevalence in dairy cattle. A total of 416 bovine blood samples were collected from 30 farms, and N. caninum antibody levels were measured by Indirect Fluorescent Antibody Test (IFAT). Analysis of dairy cattle serum samples revealed the presence of anti-N. caninum antibodies to be 47.36% (n = 197). Risk factors associated with N. caninum infection were the management system and access locations of dogs. The results of the present survey indicated that infection of dairy cattle with N. caninum is widespread in the studied region of Western Amazon, which has implications for prevention and control of neosporosis in this region. Therefore, integrated control strategies and measures are recommended to prevent and control N. caninum infection in dairy cattle. In addition, direct contact between dairy cattle, dogs and wild animals, which can influence the epidemiology of neosporosis, should be investigated further.(AU)

A infecção por Neospora caninum é considerada uma das principais causas de aborto entre bovinos. Esta pesquisa foi realizada no município de Rolim de Moura, estado de Rondônia, Brasil. Um questionário que investiga os aspectos epidemiológicos da neosporose foi utilizado na análise dos fatores de risco associados à prevalência em animais e em rebanhos. Um total de 416 amostras de sangue bovino foi colhido em 30 fazendas, e os níveis de anticorpos de N. caninum foram mensurados pela reação de Imunofluorescência Indireta (RIFI). A análise das amostras mostrou prevalência de anticorpos contra N. caninum de 47,36% (n = 197). Os fatores de risco associados à infecção por N. caninum foram o sistema de manejo e os locais de acesso dos cães. Os resultados da presente pesquisa indicam que a infecção de bovinos leiteiros com N. caninum está disseminada na região estudada da Amazônia Ocidental, o que tem implicações para a prevenção e controle da neosporose nessa região. Portanto, estratégias e medidas de controle integrado são recomendadas para prevenir e controlar a infecção por N. caninum em gado leiteiro. Além disso, o contato íntimo entre gado leiteiro, cães e animais selvagens, pode influenciar a epidemiologia da neosporose e deve ser investigada mais detalhadamente.(AU)

Causes of abortion in dairy cows in Uruguay / Causas de aborto em bovinos de leite no Uruguai

A case series study was conducted to determine the frequency of causes of abortion in dairy cattle in Uruguay. The sample size of 102 cases was composed of 53 fetuses, 35 fetuses with placentas, and 14 placentas without an associated fetus. All cases underwent gross and microscopic pathologic examinations as well as microbiological and serological testing. The etiology was determined in 54 (53%) of cases, 51 of which were caused by infectious agents. Within the observed 102 cases, 30 (29%) were caused by Neospora caninum, six (6%) by Coxiella burnetii and two (2%) by Campylobacter fetus subsp. venerealis. Bovine Parainfluenza-3 virus and Salmonella enterica serovar Newport caused one abortion each. Opportunistic bacteria (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes, and Providencia stuartii) were associated with 11 abortions. In two cases the fetal death was attributed to dystocia, and in one case the fetus had a congenital mesothelioma. Bovine viral diarrhea virus (BVDV) infection was identified in three fetuses; two of which were co-infected with and had typical lesions of N. caninum. No lesions were observed in the other fetus infected by BVDV. Leptospira interrogans was identified in one fetus without lesions. Despite the relatively low overall success rate in establishing an etiological diagnosis in cases of abortion in cattle, a systemic workup of bovine abortion is necessary to establish prevention and control strategies. This also facilitates monitoring and surveillance of reproductive diseases in dairy cattle, some of which represent a risk to public health.(AU)

Uma série de casos foi estudada para determinar a frequência de causas do aborto em bovinos leiteiros no Uruguai. A amostra, de 102 casos, foi composta por 53 fetos, 35 fetos com placentas e 14 placentas sem feto associado. Todos os casos foram submetidos a exames patológicos macroscópicos e microscópicos, além de testes microbiológicos e sorológicos. A etiologia foi determinada em 54 (53%) dos casos, 51 dos quais foram causados por agentes infecciosos. Nos 102 casos observados, 30 (29%) foram causados por Neospora caninum, seis (6%) por Coxiella burnetii e dois (2%) por Campylobacter fetus subsp. venerealis. O vírus da Parainfluenza-3 e Salmonella enterica serovar Newport causaram um aborto cada. Bactérias oportunistas (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes e Providencia stuartii) foram associadas a 11 abortos. Em dois casos, a morte fetal foi atribuída a distocia e, em um caso, o feto apresentava mesotelioma congênito. A infecção pelo vírus da diarreia viral bovina (BVDV) foi identificada em três fetos; dois dos quais foram co-infectados e apresentavam lesões típicas de N. caninum. Não foram observadas lesões no outro feto infectado pelo BVDV. Leptospira interrogans foi identificada em um feto sem lesões. Apesar da relativamente baixa taxa de sucesso no diagnóstico etiológico nos casos de aborto em bovinos, é necessário o diagnóstico sistemático dos abortos para estabelecer estratégias de prevenção e controle. Isso também facilita o monitoramento e a vigilância de doenças reprodutivas em bovinos leiteiros, algumas das quais representam um risco para a saúde pública.(AU)

Causes of abortion in dairy cows in Uruguay / Causas de aborto em bovinos de leite no Uruguai

A case series study was conducted to determine the frequency of causes of abortion in dairy cattle in Uruguay. The sample size of 102 cases was composed of 53 fetuses, 35 fetuses with placentas, and 14 placentas without an associated fetus. All cases underwent gross and microscopic pathologic examinations as well as microbiological and serological testing. The etiology was determined in 54 (53%) of cases, 51 of which were caused by infectious agents. Within the observed 102 cases, 30 (29%) were caused by Neospora caninum, six (6%) by Coxiella burnetii and two (2%) by Campylobacter fetus subsp. venerealis. Bovine Parainfluenza-3 virus and Salmonella enterica serovar Newport caused one abortion each. Opportunistic bacteria (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes, and Providencia stuartii) were associated with 11 abortions. In two cases the fetal death was attributed to dystocia, and in one case the fetus had a congenital mesothelioma. Bovine viral diarrhea virus (BVDV) infection was identified in three fetuses; two of which were co-infected with and had typical lesions of N. caninum. No lesions were observed in the other fetus infected by BVDV. Leptospira interrogans was identified in one fetus without lesions. Despite the relatively low overall success rate in establishing an etiological diagnosis in cases of abortion in cattle, a systemic workup of bovine abortion is necessary to establish prevention and control strategies. This also facilitates monitoring and surveillance of reproductive diseases in dairy cattle, some of which represent a risk to public health.(AU)

Uma série de casos foi estudada para determinar a frequência de causas do aborto em bovinos leiteiros no Uruguai. A amostra, de 102 casos, foi composta por 53 fetos, 35 fetos com placentas e 14 placentas sem feto associado. Todos os casos foram submetidos a exames patológicos macroscópicos e microscópicos, além de testes microbiológicos e sorológicos. A etiologia foi determinada em 54 (53%) dos casos, 51 dos quais foram causados por agentes infecciosos. Nos 102 casos observados, 30 (29%) foram causados por Neospora caninum, seis (6%) por Coxiella burnetii e dois (2%) por Campylobacter fetus subsp. venerealis. O vírus da Parainfluenza-3 e Salmonella enterica serovar Newport causaram um aborto cada. Bactérias oportunistas (Escherichia coli, Streptococcus sp., Staphylococcus sp., Mannheimia sp., Trueperella pyogenes e Providencia stuartii) foram associadas a 11 abortos. Em dois casos, a morte fetal foi atribuída a distocia e, em um caso, o feto apresentava mesotelioma congênito. A infecção pelo vírus da diarreia viral bovina (BVDV) foi identificada em três fetos; dois dos quais foram co-infectados e apresentavam lesões típicas de N. caninum. Não foram observadas lesões no outro feto infectado pelo BVDV. Leptospira interrogans foi identificada em um feto sem lesões. Apesar da relativamente baixa taxa de sucesso no diagnóstico etiológico nos casos de aborto em bovinos, é necessário o diagnóstico sistemático dos abortos para estabelecer estratégias de prevenção e controle. Isso também facilita o monitoramento e a vigilância de doenças reprodutivas em bovinos leiteiros, algumas das quais representam um risco para a saúde pública.(AU)

Neospora caninum and Toxoplasma gondii: seroprevalence and associated factors in cows from milk farms of Toledo, Parana, Brazil / Neospora caninum e Toxoplasma gondii: soroprevalência e fatores associados em vacas leiteiras de Toledo, Paraná, Brasil

Neospora caninum and Toxoplasma gondii are important protozoa in cattle production. Neosporosis is responsible for reproductive failures in cattle, constituting one of the main causes of abortion and leading to significant economic losses in dairy farming. Toxoplasmosis is a cosmopolitan disease of great importance in the context of public health and animal production. Considering the lack of available data on the subject for the studied region, the objective of the present study was to detect the seroprevalence of antibodies against N. caninum and T. gondii in dairy cows in the municipality of Toledo, Western Paraná, Brazil and to assess how to detect factors associated with risk or protection. Serology was performed with serum samples from 390 dairy cows from 58 farms by indirect immunofluorescence (IFI) reaction using cutoff point 100 for N. caninum and 64 for T. gondii. The analysis of associations between seropositivity and the variables detected in the properties was also performed. The seroprevalence for Neospora caninum was 15.4% (60/390; CI 95% 12.4-19.3) and for Toxoplasma gondii was 38.7% (151/390; CI 95% 34.0-43.6). The prevalence of co-infection was 8.72% (34/390; CI 95% 6.31-11.94). For N. caninum, the presence of abortion was observed as a risk factor (OR= 5.32). With T. gondii, the presence of abortion was found to be a risk factor (OR= 2.09) and properties with 10 or more lactating animals was found to be a protection factor (OR= 0.56). Abortion was also detected as a factor associated with the risk of co-infection (OR= 11.80). Through serological diagnosis, the present study showed that protozoa are widely distributed among dairy cattle in the region, and control and prophylaxis measures should be adopted in the studied animal population. Because abortion is a risk associated with N. caninum, T. gondii, and the two agents surveyed (co-infection), all reproductive disorders detected in cattle should include neosporosis and toxoplasmosis as a differential diagnosis.(AU)

Neospora caninum e Toxoplasma gondii são protozoários importantes na cadeia produtiva dos bovinos. A neosporose é responsável por falhas reprodutivas nesta espécie, constituindo uma das principais causas de abortamento, levando a significativas perdas econômicas na pecuária leiteira. A toxoplasmose é uma doença cosmopolita, com grande importância no contexto de saúde pública e produção animal. Considerando a escassez de dados disponíveis sobre o tema para a região estudada, o objetivo do presente estudo foi detectar a soroprevalência de anticorpos contra N. caninum e T. gondii em fêmeas de bovinos leiteiros no município de Toledo, Oeste do Paraná, Brasil, bem como detectar os fatores associados ao risco ou proteção. A sorologia foi realizada com amostras de soro de 390 fêmeas bovinas leiteiras provenientes de 58 propriedades rurais, pela reação de Imunofluorescência Indireta (IFI) utilizando ponto de corte 100 para o N. caninum e 64 para o T. gondii. Também foi procedida as análises das associações entre a soropositividade e as variáveis detectadas nas propriedades. A soroprevalência encontrada para o Neospora caninum foi de 15,4% (60/390; IC 95% 12,4-19,3) e para o Toxoplasma gondii foi de 38,7% (151/390; IC 95% 34,0-43,6), sendo que a co-infecção detectada foi de 8,72% (34/390; IC 95% 6,31-11,94). Para o N. caninum foi observado como fator associado ao risco a presença de aborto (OR= 5,32). Já para o T. gondii, como fatores associados ao risco, foi encontrado a presença de aborto (OR= 2,09) e como fator associado à proteção, foi detectado propriedades com 10 ou mais animais em lactação (OR= 0,56). O aborto foi também detectado como um fator associado ao risco da co-infecção (OR= 11,80). Através do diagnóstico sorológico o presente estudo evidenciou que os protozoários estão amplamente distribuídos entre os bovinos leiteiros da região e medidas de controle e profilaxia devem ser adotadas na população animal estudada. Devido ao aborto ser uma associação de risco para o N. caninum, para o T. gondii e para os dois agentes pesquisados (co-infecção), todas as desordens reprodutivas detectadas em bovinos devem incluir a neosporose e a toxoplasmose como diagnóstico diferencial.(AU)

Current trends in bovine abortion in Argentina / Tendências atuais do aborto bovino na Argentina

Bovine abortion is an important cause of significant economic losses in beef and dairy herds. This syndrome is usually difficult to diagnose. The aim of this study was to characterize bovine abortion causes in Argentina by standard diagnosis procedures (histology, bacterial and viral isolation) and other diagnostic tests like direct fluorescent antibody test (DFAT), fetal serology, immunohistochemistry (IHC), and PCR, showing their specific advantages and limitations. Necropsies were performed in 150 aborted bovine fetuses submitted to the diagnostic laboratories of Instituto Nacional de Tecnología Agropecuaria (INTA) Balcarce, Argentina. Etiological diagnosis was confirmed in 78 fetuses (52% of the cases). Most causes of abortion were of infectious origin, being Neospora caninum (14.67%), Campylobacter fetus sp. (9.33%), Leptospira spp. (7.33%) and Brucella abortus (6.65%) the main microorganisms identified. Bovine viral diarrhea virus (BVDV) and bovine herpes virus (BHV) were diagnosed in 2 (1.33%) and 3 (2%) cases, respectively. This study showed a better characterization of bovine abortion compared with previous researches done on this topic.(AU)

O aborto bovino é uma causa importante de perdas econômicas significativas em rebanhos bovinos e leiteiros. Esta síndrome é geralmente difícil de diagnosticar. O objetivo deste estudo foi caracterizar o aborto bovino na Argentina por procedimentos diagnósticos de rotina (histologia, isolamento viral e bacteriana) e outros testes diagnósticos como ensaio directo de anticorpos fluorescentes (DFAT), sorologia fetal, imuno-histoquica (IHC), e PCR; mostrando suas vantagens e limitações específicas. As necropsias foram realizadas em 150 fetos bovinos abortados submetidos aos laboratórios de diagnóstico do Instituto Nacional de Tecnologia Agropecuária (INTA) de Balcarce, na Argentina. O diagnóstico etiológico foi confirmado em 78 fetos (52% dos casos). A maioria das causas de aborto foram de origem infecciosa, sendo Neospora caninum (14,67%), Campylobacter fetus sp. (9,33%), Leptospira spp. (7,33%) e Brucella abortus (6,65%) os principais microrganismos identificados. O vírus da diarréia viral bovina (BVDV) e o herpesvírus bovino (BHV) foram diagnosticados em 2 (1,33%) e 3 (2%) casos, respectivamente. Este estudo mostrou uma melhor caracterização do aborto bovino em comparação com pesquisas anteriores feita sobre este tema.(AU)

Current trends in bovine abortion in Argentina / Tendências atuais do aborto bovino na Argentina

Bovine abortion is an important cause of significant economic losses in beef and dairy herds. This syndrome is usually difficult to diagnose. The aim of this study was to characterize bovine abortion causes in Argentina by standard diagnosis procedures (histology, bacterial and viral isolation) and other diagnostic tests like direct fluorescent antibody test (DFAT), fetal serology, immunohistochemistry (IHC), and PCR, showing their specific advantages and limitations. Necropsies were performed in 150 aborted bovine fetuses submitted to the diagnostic laboratories of Instituto Nacional de Tecnología Agropecuaria (INTA) Balcarce, Argentina. Etiological diagnosis was confirmed in 78 fetuses (52% of the cases). Most causes of abortion were of infectious origin, being Neospora caninum (14.67%), Campylobacter fetus sp. (9.33%), Leptospira spp. (7.33%) and Brucella abortus (6.65%) the main microorganisms identified. Bovine viral diarrhea virus (BVDV) and bovine herpes virus (BHV) were diagnosed in 2 (1.33%) and 3 (2%) cases, respectively. This study showed a better characterization of bovine abortion compared with previous researches done on this topic.(AU)

O aborto bovino é uma causa importante de perdas econômicas significativas em rebanhos bovinos e leiteiros. Esta síndrome é geralmente difícil de diagnosticar. O objetivo deste estudo foi caracterizar o aborto bovino na Argentina por procedimentos diagnósticos de rotina (histologia, isolamento viral e bacteriana) e outros testes diagnósticos como ensaio directo de anticorpos fluorescentes (DFAT), sorologia fetal, imuno-histoquica (IHC), e PCR; mostrando suas vantagens e limitações específicas. As necropsias foram realizadas em 150 fetos bovinos abortados submetidos aos laboratórios de diagnóstico do Instituto Nacional de Tecnologia Agropecuária (INTA) de Balcarce, na Argentina. O diagnóstico etiológico foi confirmado em 78 fetos (52% dos casos). A maioria das causas de aborto foram de origem infecciosa, sendo Neospora caninum (14,67%), Campylobacter fetus sp. (9,33%), Leptospira spp. (7,33%) e Brucella abortus (6,65%) os principais microrganismos identificados. O vírus da diarréia viral bovina (BVDV) e o herpesvírus bovino (BHV) foram diagnosticados em 2 (1,33%) e 3 (2%) casos, respectivamente. Este estudo mostrou uma melhor caracterização do aborto bovino em comparação com pesquisas anteriores feita sobre este tema.(AU)

Trueperella pyogenes como causa de aborto em uma vaca - relato de caso / Trueperella pyogenes as an abortion cause in a cow - case report

Trueperella pyogenes é uma bactéria oportunista que causa mastite, metrite e abortos esporádicos em bovinos. Este trabalho relata um caso incomum de abort em uma vaca por Trueperella pyogenes. Um feto bovino, fêmea, mestiço Brahman, com oito meses de gestação, foi encaminhado para exame anatomopatológico e exames complementares. Na necropsia, evidenciou-se grande quantidade de líquido serossanguinolento e moderada quantidade de fibrina recobrindo a pleura visceral e o saco pericárdico. Os pulmões estavam difusamente avermelhados e consolidados, com áreas firmes esbranquiçadas ao corte de não mais de 1cm. No exame histopatológico, observou-se pneumonia necrossupurativa, pleurite fibrinopurulenta e placentite purulenta. No exame microbiológico, isolou-se T. pyogenes nas amostras de fígado, pulmões, conteúdo abomasal do feto e placenta. O feto foi negativo na PCR para Neospora caninum, Toxoplasma gondii e vírus da diarreia viral bovina (BVDV). Trueperella pyogenes geralmente causa broncopneumonia supurativa com formação de abscessos, porém, no presente feto abortado, observaram-se lesões macro e microscópicas comumente descritas em casos de aborto por Brucella abortus. Este estudo constata, então, a importância dessa bactéria como causa de aborto em bovinos, com lesões semelhantes à brucelose, destacando sua relevância dentro das causas de aborto em bovinos e o potencial zoonótico pouco explorado.(AU)

Trueperella pyogenes is an opportunistic bacterium associated with mastitis, metritis and occasional abortion in bovines. Here we report an uncommon case of abortion by T. pyogenes in a cow. An aborted female Brahman bovine fetus, at 8 months of gestational age was submitted for anatomopathological examination and complementary diagnostic tests. Macroscopic findings at necropsy included large amounts of free serum-blood fluid and moderate fibrin deposition covering both the visceral pleura and pericardial sack. The lungs were diffusely reddened and markedly consolidated, showing widespread smaller than 1cm, hard, white nodules. Necrosuppurative pneumonia, fibrinopurulent pleuritis, and purulent placentitis were the main histopathologic alterations observed. Trueperella pyogenes was isolated from liver, lungs, abomasa contents and placental samples. All tissue samples were PCR-negative for Neospora caninum, Toxoplasma gondii and bovine viral diarrhea virus (BVDV). Although T. pyogenes is often involved in suppurative bronchopneumonia and abscesses formation, macro and microscopic lesions in the present report were compatible with those commonly attributed to Brucella abortus fetal infections. Trueperella pyogenes is an important bovine pathogen with a neglected zoonotic potential being responsible for infections that can mimic other diseases' typical presentations.(AU)

Trueperella pyogenes como causa de aborto em uma vaca - relato de caso / Trueperella pyogenes as an abortion cause in a cow - case report

Trueperella pyogenes é uma bactéria oportunista que causa mastite, metrite e abortos esporádicos em bovinos. Este trabalho relata um caso incomum de abort em uma vaca por Trueperella pyogenes. Um feto bovino, fêmea, mestiço Brahman, com oito meses de gestação, foi encaminhado para exame anatomopatológico e exames complementares. Na necropsia, evidenciou-se grande quantidade de líquido serossanguinolento e moderada quantidade de fibrina recobrindo a pleura visceral e o saco pericárdico. Os pulmões estavam difusamente avermelhados e consolidados, com áreas firmes esbranquiçadas ao corte de não mais de 1cm. No exame histopatológico, observou-se pneumonia necrossupurativa, pleurite fibrinopurulenta e placentite purulenta. No exame microbiológico, isolou-se T. pyogenes nas amostras de fígado, pulmões, conteúdo abomasal do feto e placenta. O feto foi negativo na PCR para Neospora caninum, Toxoplasma gondii e vírus da diarreia viral bovina (BVDV). Trueperella pyogenes geralmente causa broncopneumonia supurativa com formação de abscessos, porém, no presente feto abortado, observaram-se lesões macro e microscópicas comumente descritas em casos de aborto por Brucella abortus. Este estudo constata, então, a importância dessa bactéria como causa de aborto em bovinos, com lesões semelhantes à brucelose, destacando sua relevância dentro das causas de aborto em bovinos e o potencial zoonótico pouco explorado.(AU)

Trueperella pyogenes is an opportunistic bacterium associated with mastitis, metritis and occasional abortion in bovines. Here we report an uncommon case of abortion by T. pyogenes in a cow. An aborted female Brahman bovine fetus, at 8 months of gestational age was submitted for anatomopathological examination and complementary diagnostic tests. Macroscopic findings at necropsy included large amounts of free serum-blood fluid and moderate fibrin deposition covering both the visceral pleura and pericardial sack. The lungs were diffusely reddened and markedly consolidated, showing widespread smaller than 1cm, hard, white nodules. Necrosuppurative pneumonia, fibrinopurulent pleuritis, and purulent placentitis were the main histopathologic alterations observed. Trueperella pyogenes was isolated from liver, lungs, abomasa contents and placental samples. All tissue samples were PCR-negative for Neospora caninum, Toxoplasma gondii and bovine viral diarrhea virus (BVDV). Although T. pyogenes is often involved in suppurative bronchopneumonia and abscesses formation, macro and microscopic lesions in the present report were compatible with those commonly attributed to Brucella abortus fetal infections. Trueperella pyogenes is an important bovine pathogen with a neglected zoonotic potential being responsible for infections that can mimic other diseases' typical presentations.(AU)

Risk factors for enzootic leukosis in dairy cattle from the Brazilian Amazon

Background: Enzootic bovine leukosis (EBL) is a viral and lymphoproliferative disease that attributes negative economicimpacts to dairy farming. The immunosuppressive condition of these bovines favors the development of bacterial diseases such as tuberculosis, brucellosis, and bovine leptospirosis, which implications to the public health given that theyare zoonosis. Diagnosis and control of EBL are neglected in cattle rearing, allowing their dissemination, especially indeveloping countries. In this sense, the objective of this study was to analyze the risk factors of EBL in dairy cattle fromthe Brazilian Amazon.Materials, Methods & Results: In order to identify the BLV-infected animals (527 serological samples), we used theagarose gel immunodiffusion serological test (IDGA) to diagnose the EBL and characterize the risk factors through theapplication of epidemiological questionnaires. We used the logistic regression test to evaluate the existence of a significantassociation between the variables. The EBL frequency in the study area was 14.42%. We detected seroreagent bovines inall municipalities evaluated with 95% of the properties showing outbreaks of the disease. The reuse of needles was therisk factor with the most significant statistical association (P < 0.01; OR = 2.16).Discussion: The origin of EBL in the Brazilian Amazon is probably related to the expansion of dairy cattle in the 1980s,which, at first, demanded the importation of cattle for the fast formation of the herds, without complying with the sanitarycriteria of animal commercialization. The frequency of EBL in the Rio Branco microregion is below the estimated nationalaverage, as well as the regional level. The reduced influx of animals due to the geographical situation of Acre, since itis an area of greater physical isolation due to forest and river barriers, may influence the observed frequency. Differentenvironmental...

Risk factors for enzootic leukosis in dairy cattle from the Brazilian Amazon

Background: Enzootic bovine leukosis (EBL) is a viral and lymphoproliferative disease that attributes negative economicimpacts to dairy farming. The immunosuppressive condition of these bovines favors the development of bacterial diseases such as tuberculosis, brucellosis, and bovine leptospirosis, which implications to the public health given that theyare zoonosis. Diagnosis and control of EBL are neglected in cattle rearing, allowing their dissemination, especially indeveloping countries. In this sense, the objective of this study was to analyze the risk factors of EBL in dairy cattle fromthe Brazilian Amazon.Materials, Methods & Results: In order to identify the BLV-infected animals (527 serological samples), we used theagarose gel immunodiffusion serological test (IDGA) to diagnose the EBL and characterize the risk factors through theapplication of epidemiological questionnaires. We used the logistic regression test to evaluate the existence of a significantassociation between the variables. The EBL frequency in the study area was 14.42%. We detected seroreagent bovines inall municipalities evaluated with 95% of the properties showing outbreaks of the disease. The reuse of needles was therisk factor with the most significant statistical association (P < 0.01; OR = 2.16).Discussion: The origin of EBL in the Brazilian Amazon is probably related to the expansion of dairy cattle in the 1980s,which, at first, demanded the importation of cattle for the fast formation of the herds, without complying with the sanitarycriteria of animal commercialization. The frequency of EBL in the Rio Branco microregion is below the estimated nationalaverage, as well as the regional level. The reduced influx of animals due to the geographical situation of Acre, since itis an area of greater physical isolation due to forest and river barriers, may influence the observed frequency. Differentenvironmental...(AU)

Association of abortion history with the presence of anti-Neospora caninum antibodies in dairy cows / Associação do histórico de abortamento com a presença de anticorpos anti-Neospora caninum em vacas leiteiras

Neospora caninum is an important cause of abortions in dairy cattle, leading to severe economic losses. The objective of this study was to determine the association of serum antibodies against N. caninum with a history of abortion in dairy cows. A total of 46 dairy cows from nine dairy farms were evaluated; 28 with a history of one or more abortions and 18 without a history of abortions. Antibodies against N. caninum were detected by indirect immunofluorescence, and the reaction was considered positive when the titer was ?1:50. Serum antibodies against N. caninum were detected in 39.1% (18/46) of all cows, 57.1% (16/28) of cows with a history of abortion, and 11.1% (2/18) of cows without a history of abortion. Among the seropositive cows, 88.9% had a history of abortion. All farms showed at least one animal positive for N. caninum. These results indicate an association between seropositivity for N. caninum and a history of abortion in cows. Cows with a history of abortion were 10.6 times more likely to be seropositive for N. caninum than cows without a history of abortion. Therefore, we concluded that there is an association between a history of abortion and the presence of antibodies against N. caninum in dairy cows.(AU)

O Neospora caninum é um importante agente causador de abortos em bovinos leiteiros, promovendo severos prejuízos econômicos. Objetivou-se neste trabalho associar a presença de anticorpos contra N. caninum com histórico de abortamento em vacas leiteiras. Um total de 46 vacas leiteiras foram avaliadas, sendo 28 com histórico de um ou mais abortamentos e 18 sem histórico de abortamentos, provenientes de nove propriedades leiteiras. Para a detecção de anticorpos contra N. caninum foi realizada a reação de imunofluorescência indireta, sendo consideradas positivas quando os títulos foram maiores ou iguais a 1:50. A soro ocorrência de anticorpos contra N. caninum entre todas as vacas avaliadas foi de 39,1% (18/46), entre as vacas com histórico de abortamento foi de 57,1% (16/28) e de 11,1% (2/18) nas vacas que não haviam abortado. Dentre as vacas soropositivas, 88,9% possuíam histórico de aborto. Todas as propriedades avaliadas apresentaram animais com anticorpos contra o N. caninum. Há uma associação entre vacas soropositivas para N. caninum e histórico de abortamento. Vacas soropositivas apresentaram 10,6 vezes mais chances de serem sororreagentes ao Neospora caninum do que vacas sem histórico de abortamento. Conclui-se que existe associação entre histórico de abortamento e presença de anticorpos contra Neospora caninum em vacas leiteiras.(AU)

Utilização de um teste ELISA indireto para o diagnostico da brucelose em amostras de soro de búfalas / Use of a test indirect ELISA for the diagnosis of brucellosis in buffaloes serum samples

Devido os males provocados pela Brucelose na produção de búfalos, o presente trabalho teve como objetivo comparar o desempenho dos testes de Antígeno Acidificado Tamponado (AAT) e Ensaio Imunoenzimático (ELISA) indireto, na investigação da Brucella abortus em soro de fêmeas bubalinas. Das 118 amostras de soros examinados através na técnica AAT, nenhuma amostra foi reagente a técnica. Assim, as mesmas amostras foram testadas pelo método de ELISA Indireto, onde encontrou-se 82 amostras reagentes. Dessa forma, conclui-se que a técnica do ELISA Indireto para teste de diagnóstico de triagem em bubalinos é uma boa opção por possuir excelente desempenho.(AU)

Regarding to the effects of brucellosis in buffalo production, this study were designed to compare the acidified buffered Antigen diagnostic test to indirect ELISA test performance in serum buffalo females. Samples analyzed by ATT technique did not reacted, nevertheless the same samples were submitted in indirect ELISA test and 82 were reacted positively. In accordance with this results, was concluded that the Indirect ELISA test is the best choice to the brucellosis diagnostic.(AU)

Utilização de um teste ELISA indireto para o diagnostico da brucelose em amostras de soro de búfalas / Use of a test indirect ELISA for the diagnosis of brucellosis in buffaloes serum samples

Devido os males provocados pela Brucelose na produção de búfalos, o presente trabalho teve como objetivo comparar o desempenho dos testes de Antígeno Acidificado Tamponado (AAT) e Ensaio Imunoenzimático (ELISA) indireto, na investigação da Brucella abortus em soro de fêmeas bubalinas. Das 118 amostras de soros examinados através na técnica AAT, nenhuma amostra foi reagente a técnica. Assim, as mesmas amostras foram testadas pelo método de ELISA Indireto, onde encontrou-se 82 amostras reagentes. Dessa forma, conclui-se que a técnica do ELISA Indireto para teste de diagnóstico de triagem em bubalinos é uma boa opção por possuir excelente desempenho.

Regarding to the effects of brucellosis in buffalo production, this study were designed to compare the acidified buffered Antigen diagnostic test to indirect ELISA test performance in serum buffalo females. Samples analyzed by ATT technique did not reacted, nevertheless the same samples were submitted in indirect ELISA test and 82 were reacted positively. In accordance with this results, was concluded that the Indirect ELISA test is the best choice to the brucellosis diagnostic.

Occurrence of antibodies against Neospora caninum in cattle and dogs from dairy farms from the central northern region of Paraná State / Ocorrência de anticorpos contra Neospora caninum em bovinos e cães oriundo de propriedades produtoras de leite do Norte Central do Estado do Paraná

Neosporosis is one of the principal causes of reproductive problems in cattle worldwide. The aim of this study was to evaluate the occurrence of anti-Neospora caninum antibodies in cattle and dogs from dairy farms from the central northern region of Paraná state. Blood samples with and without EDTA were collected from 400 cattle and 46 dogs from 20 properties. Nested polymerase chain reaction (n-PCR) was performed on whole blood samples and indirect immunofluorescence reaction (IFR) on the serum samples (after clot retraction). Cattle and dogs with titers ? 100 and ? 50, respectively, were considered positive. Anti-N. caninum was detected in 20,1% (80/400) of cattle, with titers ranging from 100 to 1600. The n-PCR presented only two cattle positives (0.5%). Anti-N. caninum was detected in 19,6% (9/46) of the dogs, with titers ranging from 50 to 6400. The occurrence of antibodies against N. caninum obtained in the present study was similar to those in studies performed in other regions of Paraná and Brazil. The probability of detecting parasitemia in epidemiological studies is a rare event.(AU)

A neosporose é uma das principais causas de abortamentos em bovinos no mundo todo. O objetivo do presente estudo foi avaliar a ocorrência de anticorpos contra Neospora caninum em soros de bovinos de leite e cães provenientes de propriedades da região centro norte do estado do Paraná. Sangue com e sem EDTA foram colhidos de 400 bovinos e de 46 cães provenientes de 20 propriedades. Para detecção de anticorpos contra N. caninum a Reação de Imunofluorescência Indireta (RIFI) foi realizada, e bovinos e cães foram considerados positivos quando apresentaram títulos ? 100 e ? 50, respectivamente. Anticorpos contra-N. caninum foram detectados em 20,1% (80/400) dos bovinos, cujos títulos variaram de 100 a 1600. A n-PCR apresentou apenas dois animais positivos (0,5%) para os bovinos. Dos 46 cães estudados 19,6% (9/46) foram considerados positivos na RIFI, com títulos variando de 50 a 6400. Os resultados permitem concluir que a ocorrência de anticorpos contra N. caninum em bovinos e cães na mesorregião centro norte do Paraná foram semelhantes aos observados em outras mesorregiões do Paraná. A n-PCR de sangue total revelou uma baixa positividade em bovinos e cães, mostrando que a probabilidade de se detectar parasitemia em estudos epidemiológicos é baixa.(AU)

Seroprevalence, spatial analysis and risk factors of infection with Neospora caninum in cattle in Brazil's northern Pantanal wetland / Soroprevalência, análise espacial e fatores de risco da infecção por Neospora caninum em bovinos no Pantanal norte do Brasil

Neosporosis is caused by an obligate intracellular protozoan, Neospora caninum . It is considered one of the most widespread and frequent causes of abortion in cattle worldwide. To evaluate the prevalence of anti-N. caninum antibodies and associated risk factors, serum samples were collected from 2,452 bovines at 262 farms in the northern Pantanal, state of Mato Grosso, Brazil. Each farmer was asked to fill out a questionnaire for subsequent epidemiological data analysis. Anti-N. caninum antibodies were detected by means of the indirect immunofluorescent assay (IFA), using a cut-off dilution of 1:100. The overall anti-N. caninum antibodies prevalence was 25.44% (Confidence Interval - CI 95%; 20.10%; 30.78%), and the anti-N. caninum antibodies prevalence per herd was 76.72% (CI 95%; 71.60%; 81.84%). The presence of dogs, occurrence of abortion in cows, and sale of cattle for breeding were statistically associated with seropositivity in herds, while the risk of females being seropositive for N. caninum was higher in animals 6-years-old and in the presence of dogs. A spatial analysis indicated that the relative risk of the disease is spatially constant and that the farms with the highest prevalence of anti-N. caninum antibodies are located south of the region under study.(AU)

Neosporose é causada por um protozoário intracelular obrigatório, Neospora caninum. É considerada uma das causas mais comuns e frequentes de aborto em bovinos em todo o mundo. Para avaliar a prevalência de anticorpos anti- N. caninum e fatores de risco associados, amostras de soro foram coletadas de 2.452 bovinos em 262 fazendas no Pantanal norte, estado de Mato Grosso, Brasil. Cada fazendeiro preencheu um questionário para posterior análise dos dados epidemiológicos. Anticorpos anti-N. caninum foram detectados por meio da reação de imunofluorescência indireta (RIFI), utilizando um ponto de corte de 1:100. A prevalência total de anticorpos anti-N. caninum foi de 25,44% (Intervalo de Confiança - IC 95%; 20,10%; 30,78%) e a prevalência por rebanho foi de 76,72% (IC 95%; 71,60%; 81,84%). A presença de cães, a ocorrência de abortamento em vacas e a venda de bovinos para reprodução estiveram estatisticamente associadas à soropositividade em rebanhos, enquanto, o risco de fêmeas serem soropositivas para N. caninum foi maior em animais com idade 6 anos e na presença de cães. A análise espacial indicou que o risco relativo da doença é espacialmente constante e que as fazendas com maior prevalência de anticorpos anti-N. caninum estão localizados ao sul da região em estudo.(AU)

Infection by Neospora caninum in dairy cattle belonging to family farmers in the northern region of Brazil / Infecção por Neospora caninum em bovinos leiteiros de agricultores familiares da região norte do Brasil

Neosporosis is considered a major cause of abortion among cattle worldwide. The aim of this study was to investigate the prevalence of anti-Neospora caninum antibodies in dairy cattle and correlate them with possible risk factors on 63 small farms (family farms) in the municipality of Ji-Paraná, the main milk-producing region of the state of Rondônia, northern Brazil. For this purpose, 621 serum samples were collected from cows and were evaluated by means of the indirect fluorescence antibody test (IFAT). The overall herd prevalence of N. caninum antibodies among the farms (38/63, 60.31%) showed that N. caninum are widespread among the dairy herds in this region, despite only infecting a small proportion of animals (66/621, 10.62%). Occurrences of abortion and birth of weak calves were the only variables that showed as risk factors for the presence of N. caninum. The result from the spatial lag model strongly indicated that birth of weak calves and presence of N. caninum are occurring on farms that are located close to each other, indicating aggregation of disease occurrence.(AU)

Neosporose é considerada uma das principais causas de aborto em rebanhos bovinos em todo o mundo. O objetivo deste estudo foi investigar a prevalência de anticorpos anti-Neospora caninum em bovinos de leite e correlacioná-los com possíveis fatores de risco em 63 pequenas propriedades rurais (agricultura familiar), no município de Ji-Paraná, uma das principais regiões produtoras de leite do Estado de Rondônia, norte do Brasil. Para este propósito, 621 amostras de soro foram coletadas de vacas leiteiras e avaliadas por meio da reação de imunofluorescência indireta (RIFI). A prevalência total de propriedades com animais positivos a anticorpos anti-N. caninum (38/63, 60,31%) indica que o parasito está difundido entre os rebanhos leiteiros da região, apesar de infectar uma pequena proporção de animais (66/621, 10,62%). Ocorrência de abortos e nascimento de bezerros fracos foram as únicas variáveis consideradas como fatores de risco para a ocorrência de N. caninum. O resultado do modelo de análise espacial indica que o nascimento de bezerros fracos e a presença de N. caninum estão aparecendo em fazendas localizadas próximas umas das outras, indicando a ocorrência de agregação da doença.(AU)