Cases Of Bovine Abortion Research Articles

STUDY OF FACTORS INFLUENCING NOTIFICATION OF BOVINE ABORTIONS BY PRACTICING VETERINARIANS ON DAIRY CATTLE FARMS IN EASTERN ALGERIA.

Bovine abortion is one of the most important causes of economic losses in Algerian cattle farms and industry. A descriptive epidemiological survey was conducted from November 2021 to November 2022 in eastern Algeria to quantify the extent of this scourge and to evaluate the risk factors for reporting abortions using a questionnaire intended for 150 practising veterinarians randomly distributed in five wilayas of eastern Algeria. The statistical analysis of the different risk factors was carried out using a univariate and then multivariate logistic regression model. The results obtained showed that 83.3% of the veterinarians audited had had an abortion rate of more than 5% during the previous 12 months. In the multivariate logistic regression analysis, one risk factor and one protective factor were identified. Indeed, all the areas studied had a very high risk of bovine abortion cases: Batna (odds ratio [OR] = 24.53; 95% confidence interval [CI]: 1.39 - 278.66), Sétif (OR= 73.08; 95% CI: 4.37-669.68), Mila (OR= 245.22; CI: 18.51 - 2306.71) and Bordj Bou Arreridj (OR= 49.09; CI: 3.57-738.69). However, the summer season (OR= 0.23; 95% CI: 0.06 - 0.48) was considered a protective factor, designated as the period of least reporting of abortions by the audited veterinarians compared to winter and autumn.

Evaluation of fetal heart serum amyloid a concentrations in infectious cattle abortion cases

Serum amyloid A (SAA) concentrations have been investigated in diseases of human and domestic animals and increased SAA levels have been reported in infectious diseases. In the present study, we determined the fetal heart blood SAA concentrations in aborted bovine fetuses and investigated the relationship between the level of SAA and causative infectious agents. A total of 46 heart blood samples were collected from aborted bovine fetuses between July 2018 and July 2019 and were assigned to two groups according to microbiological, pathological and molecular results. Group 1: An infectious disease was diagnosed by detecting a microorganism (21 cases); Group 2: An infectious or inflammatory disease was not detected (25 cases). The fetal heart blood SAA concentrations were measured by commercial ELISA test. Serum amyloid A concentrations in aborted bovine fetuses were elevated from 6.1 to ≥40 mg/L in 17 of 21 cases in group 1. In group 2, SAA concentrations were less than 2.5 mg/L in 23 of 25 cases. This difference was statistically significant between group 1 and group 2. These findings suggest that SAA concentrations in fetal heart blood from bovine fetuses is potentially a novel marker for distinguishing between infectious and non-infectious bovine abortion cases.

Pathological and etiological characterization of cases of bovine abortion due to sporadic bacterial and mycotic infections.

Opportunistic bacteria and fungi are commonly reported causes of bovine abortion in a small percentage of fetal losses of infectious etiology in cattle. The objective of this study was to characterize the pathological and etiological findings in fetuses aborted due to secondary bacterial and fungal infections submitted for postmortem examination between 2004 and 2019 in the State of Rio Grande do Sul, Brazil. Nineteen cases of bacterial etiology and five cases of fungal etiology were assessed. In cases of bacterial etiology, gross changes were uncommon and two different microscopic patterns were observed: (1) primary bronchopneumonia with occasional dissemination in cases of Staphylococcus sp., Streptococcus sp., and Mannheimia haemolytica infections; and (2) systemic disease with sepsis in cases of Escherichia coli and Listeria sp. infections. Aspergillus sp. was the main fungal agent identified, and cases of mycotic abortion were characterized by placentitis, dermatitis, and pneumonia. Fetal membranes were available for examination in less than half of the submissions (11/24), and placental lesions were observed in all cases. This study reaffirms the importance of postmortem examinations in the determination of causes of fetal loss in cattle and highlights pathological findings commonly observed in fetuses aborted due to sporadic bacterial and fungal agents.

Spatial-temporal trends and economic losses associated with bovine abortifacients in central Argentina.

The aims of this work are, firstly, to provide the geolocalization of cases of bovine abortion with definitive diagnosis and, secondly, to estimate the economic losses due to the most frequent abortifacients diagnosed agents in cattle in Buenos Aires province, Argentina. The total beef and dairy cattle population at risk of abortion is 8,358,186 and 538,076, respectively. In beef cattle, the overall risk of abortion was estimated at 4.5% for all pregnancies, where 27.9% are due to Campylobacter fetus, Neospora caninum, Leptospira spp., Brucella abortus, and bovine viral diarrhea virus with economic losses of US$ 440 per abortion, being the annual loss to the beef industry of US$ 50,144,101. In dairy cattle, there was an 8.0% risk of suffering abortion, 26.1% produced by the same abortigenic agents. The economic losses were estimated at US$ 1,415 per abortion, which equals a total loss of US$ 17,298,498 for the dairy industry in the region. The results of this study show that infectious causes are highly prevalent in Buenos Aires province, and they caused severe economic impacts in the dairy and beef industries. Furthermore, changes in temporal trends of infectious abortion occurrence were detected, probably related to the inclusion of molecular diagnostic techniques with more sensitivity or different epidemiological or husbandry conditions in the region analyzed.

Campylobacter fetus in Abomasal Fluid from Spontaneously Aborted Bovine and Ovine Fetuses

Background: Pregnancy losses are a major concern in livestock industry due to their economic impact on producers. Campylobacter fetus subspecies fetus (Cff) and C. fetus subspecies venerealis (Cfv) are directly related to reproductive failures in ruminants. Cff colonizes the gastrointestinal tract of a wide range of hosts leading to abortion, while Cfv is restricted to genital tract being generally associated to infertility in bovine. Considering the great economic losses related to campylobacteriosis in cattle and ovine herds, this study aims to investigate the occurrence of C. fetus, considering Cff and Cfv subspecies, in bovine and ovine spontaneously aborted fetuses in state of Rio Grande do Sul, Brazil.Materials, Methods & Results: In this study, samples of abomasal fluid collected from 30 spontaneously aborted bovine (n = 18) and ovine (n = 12) fetuses were investigated for the detection of Campylobacter fetus throughout conventional PCR. Positive fetuses for C. fetus presence were further analyzed by molecular assays for Cff and Cfv detection, in order to determine subspecies identification. When available, samples of the main organs of the thoracic and abdominal cavities, as well as the brain, skeletal muscle, eyelid, skin, and placenta were collected for further histopathological analyses and bacterial culture, aiming to assess the presence of infection lesions and pathogens in those sites, respectively. Additionally, RT-qPCR assays were also performed for the detection of ruminant pestivirus, in order to detect bovine viral diarrhea cases. Throughout the present methodology, C. fetus was detected in the abomasal fluid samples of 2 bovine fetuses, being both identified as Cfv subspecies by PCR. Histopathological analyses demonstrated that macroscopic and microscopic changes found in the Cfv-positive animals were not either specific or directly related to Campylobacter infections. Moreover, no significant bacterial growth was observed in microbiological culture from the collected tissues, and both fetuses were negative for ruminant pestivirus. Differently, there was no detection of C. fetus in any of the analyzed ovine fetuses.Discussion: Considering that abortion diagnosis rates reported in cattle and sheep industry are highly variable among the published studies, and that abortion diagnoses are commonly inconclusive due to difficulties in sampling methodology and inadequate identification of the pathogen involved, it is important to investigate the etiological causes of abortion the herds for better understanding the causes of pregnancy issues and monitoring their occurrence. In addition, the absence of pathognomonic lesions in the tissues investigated in the histopathological analyses observed in this study strongly suggests that well-known etiological agents commonly associated to abortion, such as Leptospira spp., Toxoplasma spp., Chlamydia spp. and Neospora caninum, are unlikely to be the cause of infection of the analyzed fetuses. Taking this into account, the presence of C. fetus in the abomasal fluid samples from two bovine fetuses demonstrated in the present study suggests the possible association of Cfv not only with infertility, but also with cases of bovine abortion, highlighting the importance of investigating unusual causal agents of abortions in sheep and cattle. Overall, an adequate diagnosis is essential for establishing better prevention strategies to avoid the circulation of abortion-related infectious agents in the herds.Keywords: campylobacteriosis, molecular diagnosis, venereal disease, abortion, reproductive disease.

Bovine abortion, stillbirth and neonatal death associated with Babesia bovis and Anaplasma sp. infections in southern Brazil

Anaplasmosis and babesiosis are tick-borne diseases widely disseminated in cattle herds in many parts of the world. These diseases represent important causes of death and economic losses in several countries, including Brazil, and are characterized by hemolytic disease and anemia. Animals of all ages may be affected. Although transplacental infections are known to occur, abortion, stillbirth and neonatal death directly associated with Anaplasma marginale and especially Babesia spp. infections have rarely been documented in cattle. The objective of the present study is to describe the pathological and molecular findings of two cases of bovine abortion, two cases of stillbirth and two cases of neonatal death associated with intrauterine anaplasmosis and/or babesiosis in southern Brazil. All cases occurred in beef farms in the state of Rio Grande do Sul, between 2017 and 2019. Angus and crossbred calves were affected. At the necropsy, the main gross lesions observed included different degrees of splenomegaly, enlarged and yellow liver, thick and grumous bile, pallor or jaundice of mucous membranes and carcass, and dark kidneys. Four calves also presented cherry-pink discoloration of the central nervous system. Cytological slides enabled the observation of intraerythrocytic organisms consistent with Babesia bovis (3/6) and A. marginale (2/6). Through PCR assays, it was possible to detect three cases of Babesia sp. infection alone, and one case of Anaplasma sp. infection alone. Co-infections with Anaplasma sp. and Babesia sp. were detected in two cases. These findings reaffirm that anaplasmosis and babesiosis should be considered as an important differential diagnosis of fetal loss, stillbirth and neonatal death in cattle in areas where these diseases occur.

Infectious causes of abortions in cattle - own experiences and investigations from 2018 (January-September)

In the study, the laboratory results of 150 bovine abortion cases from 2018 (January-September) are presented. Depending on the submitted sample material and the requested examination, serological, bacteriological and/or molecular biological investigations were performed to detect abortion-causing pathogens which need or do not need to be notified in Austria. In addition to animal pathogens, the zoonotic pathogens Brucella melitensis and Salmonella Dublin were detected in 1 case each and Coxiella burnetii in 2 fetuses. The results show, that because of the zoonotic potential of some pathogens, care must be taken when handling abortion material to ensure that farmers, veterinary surgeons and laboratory staff are not at risk. Taking bovine brucellosis as an example, the reappearance of previously eradicated diseases has to be expected at any time. For detailed diagnostics, fetus with placenta and blood samples from the dam should be submitted to the laboratory. According to the extensive pathogen spectrum, investigation of abortion cases is laborious and time consuming.

Multiple bovine abortions with evidence of fetal locoism from pre-clinically intoxicated dams

Chronic consumption of specific plant species from the genera Oxytropis, Astragalus, lpomeoa, and Swainsonia, commonly known as locoweeds, is well known to induce locoism in grazing animals. Locoism in cattle is characterized by sensory deficits, ataxia, behavior changes, loss of condition, and failure to grow. The toxic principle swainsonine is rapidly absorbed and distributed through the bloodstream to multiple organs where it inhibits cellular lysosomal alphamannosidase and Golgi mannosidase II, leading to lysosomal dysfunction and disruption of glycoprotein processing. Excessive mannose-rich oligosaccharide accumulations cause cytoplasmic vacuolation and cellular dysfunction. In addition to neurologic disease, chronic consumption of locoweeds is known to induce abortion and embryonic death in neurologically affected dams. We describe multiple cases of bovine abortion associated with chronic locoweed ingestion in non-clinical dams from a herd in southeastern Colorado. Neurons from the cerebral cortex, brainstem, cerebellum, and renal tubular epithelial cells displayed the characteristic cytoplasmic vacuolation observed in adult cases of locoism in the aborted animals. Although chronic ingestion of locoweed is widely known to cause early gestation embryonic death, late-term hydrops amnii, and fetal fluid accumulation, locoweed-induced abortion should be considered as a differential diagnosis for cases ofnon-infectious abortion in grazing cattle, even in the absence of maternal clinical signs. These findings indicate that the bovine fetus may be more sensitive to the abortive effects of swainsonine than previously thought.

Limited added value of fungal ITS amplicon sequencing in the study of bovine abortion

Bovine mycotic abortion is sporadic and caused by different ubiquitous and opportunistic fungi. Recently, a broad spectrum of bacterial opportunists involved in bovine abortion was revealed by 16S rRNA gene amplicon sequencing. We hypothesized that fungal organisms potentially involved in bovine abortion also might remain undetected by conventional culture. In this retrospective study, we therefore applied fungal internal transcribed spacer 2 (ITS2) region amplicon sequencing to 74 cases of bovine abortion submitted to our diagnostic service. The investigation was complemented by fungal culture and, retrospectively, by data from bacteriological, virological and parasitological analyses and histopathological examination of placentas.Fungal DNA was found in both the placentas and abomasal contents, with 92 fungal genera identified. In 18 cases, >75% of the reads belonged to one specific fungal genus: Candida (n = 7), Malassezia (n = 4), Cryptococcus (n = 3), unidentified Capnodiales (n = 3), Actinomucor (n = 1), Cystofilobasidium (n = 1), Penicillium (n = 1), Verticillum (n = 1) and Zymoseptoria (n = 1) with one case harboring two different genera. By culture, in contrast, fungal agents were detected in only 6 cases. Inflammatory and/or necrotizing lesions were found in 27/40 histologically assessed placentas. However, no lesion-associated fungal structures were detected in HE- and PAS-stained specimens. Complementary data revealed the presence of one or more non-fungal possible abortifacient: Chlamydiales, Coxiella burnetii, Leptospira spp., Campylobacter fetus subsp. fetus, Streptococcus uberis, Escherichia coli, Streptococcus pluranimalium, Bacillus licheniformis, Campylobacter fetus subsp. fetus, Serratia marcescens, Trueperella pyogenes, Schmallenbergvirus, Neospora caninum. The mycobiota revealed by sequencing did not differ between cases with or without a possible infectious etiology.Our study suggests that amplicon sequencing of the ITS2 region from DNA isolated from bovine abortion does not provide additional information or new insight into mycotic abortion and without complementary analyses may easily lead to a false interpretation of the role of fungal organisms in bovine abortion.

Neglected zoonotic agents in cattle abortion: tackling the difficult to grow bacteria

BackgroundCoxiella burnetii, Chlamydia abortus and Leptospira spp. are difficult to grow bacteria that play a role in bovine abortion, but their diagnosis is hampered by their obligate intracellular lifestyle (C. burnetii, C. abortus) or their lability (Leptospira spp.). Their importance is based on the contagious spread in food-producing animals, but also as zoonotic agents. In Switzerland, first-line routine bacteriological diagnostics in cattle abortions is regulated by national law and includes only basic screening by staining for C. burnetii due to the high costs associated with extended spectrum analysis. The aim of this study was to assess the true occurrence of these zoonotic pathogens in 249 cases of bovine abortion in Switzerland by serology (ELISA for anti-C. burnetii and C. abortus antibodies and microscopic agglutination test for anti-Leptospira spp. antibodies), molecular methods (real-time PCR and sequencing of PCR products of Chlamydiales-positive cases), Stamp’s modification of the Ziehl-Neelsen (mod-ZN) stain and, upon availability of material, by histology and immunohistochemistry (IHC).ResultsAfter seroanalysis the prevalence was 15.9% for C. burnetii, 38.5% for C. abortus and 21.4% for Leptospira spp. By real-time PCR 12.1% and 16.9% of the cases were positive for C. burnetii and Chlamydiales, respectively, but only 2.4% were positive for C. burnetii or Chlamydiales by mod-ZN stain. Sequencing of PCR products of Chlamydiales-positive cases revealed C. abortus in 10% of cases and the presence of a mix of Chlamydiales-related bacteria in 5.2% of cases. Pathogenic Leptospira spp. were detected in 5.6% of cases. Inflammatory lesions were present histologically in all available samples which were real-time PCR-positive for Chlamydiales and Leptospira spp. One of 12 real-time PCR-positive cases for C. burnetii was devoid of histological lesions. None of the pathogens could be detected by IHC.ConclusionMolecular detection by real-time PCR complemented by histopathological analysis is recommended to improve definitive diagnosis of bovine abortion cases and determine a more accurate prevalence of these zoonotic pathogens.

Amplicon sequencing of bacterial microbiota in abortion material from cattle

Abortions in cattle have a significant economic impact on animal husbandry and require prompt diagnosis for surveillance of epizootic infectious agents. Since most abortions are not epizootic but sporadic with often undetected etiologies, this study examined the bacterial community present in the placenta (PL, n = 32) and fetal abomasal content (AC, n = 49) in 64 cases of bovine abortion by next generation sequencing (NGS) of the 16S rRNA gene. The PL and AC from three fetuses of dams that died from non-infectious reasons were included as controls. All samples were analyzed by bacterial culture, and 17 were examined by histopathology. We observed 922 OTUs overall and 267 taxa at the genus level. No detectable bacterial DNA was present in the control samples. The microbial profiles of the PL and AC differed significantly, both in their composition (PERMANOVA), species richness and Chao-1 (Mann–Whitney test). In both organs, Pseudomonas was the most abundant genus. The combination of NGS and culture identified opportunistic pathogens of interest in placentas with lesions, such as Vibrio metschnikovii, Streptococcus uberis, Lactococcus lactis and Escherichia coli. In placentas with lesions where culturing was unsuccessful, Pseudomonas and unidentified Aeromonadaceae were identified by NGS displaying high number of reads. Three cases with multiple possible etiologies and placentas presenting lesions were detected by NGS. Amplicon sequencing has the potential to uncover unknown etiological agents. These new insights on cattle abortion extend our focus to previously understudied opportunistic abortive bacteria.

Comparison of diagnostic tests for the detection of bovine brucellosis in the natural cases of abortion.

Rapid and precise diagnosis in natural field cases of bovine abortion caused by Brucella abortus warrants the use of the most sensitive and reliable diagnostic methods. In the present study, bacterial isolation, serology, gross, histopathology, immunohistochemistry and polymerase chain reaction technique(s) were applied. Sero-prevalence studies showed the rate of 28.86% positive cases using the competitive ELISA. Histopathological changes were mainly seen in the placenta, fetal lungs, kidney, liver and spleen. Immunohistochemical (IHC) staining of Brucella spp. was evident as brown, finely granular intracytoplasmic staining in trophoblasts of placental sections and in section(s) of liver, lung, kidney and spleen. Twenty-eight out of the 103 samples (17 from stomach contents, 3 from placental cotyledons, 2 from vaginal discharges and 6 from pooled fetal tissues) produced 193 bp amplicon specific for Brucella genus. Moreover, the species-specific primers amplified a 498 bp amplicon which corresponded to B. abortus. Comparison of diagnostic tests revealed PCR and IHC provide a reliable test for the diagnosis of bovine brucellosis in aborted fetal tissue and placental cotyledons whereas serology is most important for detection of Brucella positive animals in a herd.

Immunohistochemical and molecular approaches for the diagnosis of Trichomonas fetus in natural cases of bovine abortion

Immunohistochemical and molecular approaches for the diagnosis of Trichomonas fetus in natural cases of bovine abortion

Evaluation of bovine abortion cases and tissue suitability for identification of infectious agents in California diagnostic laboratory cases from 2007 to 2012

Establishing a definitive cause of bovine abortion is a challenging problem faced by veterinary practitioners and diagnosticians. Detection of an infectious or noninfectious source for abortion may facilitate interventions that mitigate future fetal loss in the herd. The purposes of this study were to identify the most common causes of bovine abortion in cases submitted to the California Animal Health and Food Safety Laboratory System, Davis (CAHFS) from 2007 to 2013 and to determine if detection of infectious pathogens differed with the fetal tissue evaluated. Records of 665 bovine abortion cases of 709 animals were reviewed for pathologic diagnoses, test methods used to identify causative conditions, and which tissues yielded successful identification of infectious agents associated with abortion. Over 58% of abortions were attributed to an infectious cause and 46.9% had an infectious agent identified. The most common infectious conditions were Epizootic Bovine Abortion (EBA) (16.2% of all fetuses), other fetal bacterial infections (14.7% of all fetuses), and Neospora caninum (9.3% of all fetuses.) The bacterium associated with EBA (currently named Pajaroellobacter abortibovis) was most commonly identified by immunohistochemistry (IHC) in lymphoid organs (thymus and spleen); N. caninum IHC was most frequently positive in brain, kidney, and placenta. In cases of pathogenic and opportunistic bacterial infections, abomasal samples yielded a significantly greater proportion of definitive aerobic culture results than lung or liver tissues. Direct fluorescent antibody test results for Bovine Viral Diarrhea Virus testing were identical between lung and kidney tissues and nearly identical (96.0%) for Bovine Herpesvirus I. Noninfectious abortive conditions included fetal stress (10.5%), dystocia (3.9%), congenital defects (3.3%), toxicological or mineral problems (1.8%), and death of the cow (1.1%). Just over 20% of the aborted fetuses had no gross or histopathological lesions to explain the abortion. This review highlights the need for submission of critical samples including abomasal contents, lymphoid tissues (thymus, spleen, and lymph nodes), and brain to maximize the diagnosticians' ability to identify causes of abortion.

Immunohistochemical and Molecular Approaches for the Diagnosis of Campylobacter fetus subsp. venerealis in Natural Cases of Bovine Abortion

Rapid and precise diagnosis in natural field cases of bovine abortion caused by Campylobacter fetus subsp. venerealis warrants use of most sensitive and reliable diagnostic methods. In the present study, an array of gross, histopathological, immunohistochemical and real time polymerase chain reaction (PCR) technique(s) for amplification of the gene encoding ISCfe1 insertion site were applied for the diagnosis of C. fetus subsp. venerealis in cases of abortion. Abortion occurred between 4 and 6 months of gestation with an average gestational age of 5 months. Histopathologically, fetal lesions recorded were bronchopneumonia and interstitial pneumonia. C. fetus with the typical morphology of spirals was observed in sections of lung with IHC staining positive reaction. In placenta, there was dense staining of clusters of the organisms which were evident as dark brown bodies showing positive reaction with IHC. Four samples (two from stomach contents, one from pooled fetal tissue and one from vaginal discharges) out of 84 tested cases were positive by real-time PCR for diagnosis of C. fetus subsp. venerealis in cases of abortion. Real time PCR techniques using ISCfe1 insertion site is most sensitive technique for diagnosis of C. fetus subsp. venerealis associated abortion.

Abortos por Neosporacaninum em bovinos do sul de Minas Gerais

Este estudo avaliou a participação de Neospora caninum em casos de abortos em bovinos provenientes de propriedades rurais da região sul de Minas Gerais por meio de análises histopatológicas, imuno-histoquímicas (IHQ) e pela reação em Cadeia de Polimerase (PCR). O material utilizado foi obtido de um estudo retrospectivo de casos de aborto recebidos pelo Setor de Patologia Veterinária da Universidade Federal de Lavras e de fetos necropsiados durante os anos de 2011 a 2013. De 60 fetos estudados, 30 (50%) tinham lesões microscópicas. Destes, 19 (63%) apresentaram lesões compatíveis com aborto por N. caninum, caracterizadas principalmente por encefalite não supurativa multifocal, necrose e gliose multifocal, assim como, miocardite e miosite não supurativa. Em 14 fetos chegou-se ao diagnóstico definitivo. Destes, cinco tiveram sua confirmação somente pela marcação IHQ e cinco foram positivos somente na PCR. Quatro fetos foram positivos tanto na IHQ quanto na PCR. Cinco fetos, provenientes do estudo retrospectivo apresentaram lesões compatíveis com N. caninum, mas a presença do protozoário não foi confirmada pela marcação IHQ. Os achados demonstram que o N. caninum é um importante agente associado ao aborto em bovinos na região sul de Minas Gerais. Para tanto, além das lesões microscópicas a associação entre a IHQ e a técnica de PCR foi essencial para a confirmação do diagnóstico.

Comparison of Diagnostic Tests for Diagnosis of Infectious Bovine Rhinotracheitis in Natural Cases of Bovine Abortion

Rapid and precise diagnosis plays a pivotal role in implementing suitable control measures in natural field cases of bovine abortion due to infection with bovine herpesvirus (BHV)-1. In the present study, serology, virus isolation, histopathology, immunohistochemistry (IHC) and real-time polymerase chain reaction (PCR) for amplification of the gene encoding glycoprotein B were applied for diagnosis of infectious bovine rhinotracheitis (IBR) in cases of abortion. The seroprevalence of IBR in the population studied was 26.3% as determined by indirect enzyme-linked immunosorbent assay. BHV-1 abortions occurred between 4 and 8 months of gestation with an average gestational age of 6 months. Affected placentae showed necrosis of chorionic villi and of the endothelium of small villous blood vessels with characteristic intranuclear (IN) acidophilic inclusion bodies. Similar inclusions were also seen in most of the tissues examined. BHV-1 antigen was identified immunohistochemically in necrotic foci in the liver, the endothelium of placental blood vessels, the bronchial epithelium and hepatocytes. Lesions in the brain also had IN inclusion bodies that labelled positively by IHC. Eighteen samples (nine of stomach content, two of placental cotyledons, five of pooled fetal tissue and two of vaginal discharge) out of 84 tested were positive by real-time PCR for BHV-1.

Detection of Infectious Bovine Rhinotracheitis in Natural Cases of Bovine Abortion by PCR and Histopathology Assays

Bovine herpesvirus 1 (BHV-1), the causative agent of infectious bovine rhinotracheitis (IBR), is considered to be the most common viral pathogen found in bovine. Bovine Herpesvirus 1(BHV-1) belongs to the genus of Varicellovirus and the family of Herpesviridae which contains three main gB, gC and gD genes. The objective of this study was to determine the relation between type of macroscopic lesions and bovine herpesvirus-1(BHV-1) infection; hence the aborted fetus specimens were initially prepared for PCR test. In this study, 23 of fetus samples, which were transferred to Veterinary Laboratories during 2009-2012, were assessed for BHV-1 with PCR in lung and spleen tissues and all of positive samples undergone histopathological study. The results indicated myocarditis and necrosis of cardiac tissue in 8 cases (42.1%), and 6 cases encompassed interstitial lymphocytic pneumonia (28.57%), whereas 5 cases revealed bronchopneumonia (23.8%) and in 8 cases (38.09%) severe interstitial edema was observed. In addition, the lesions may be associated with BHV-1, so that in brain tissue 9 cases (36 %) possessed encephalitis and necrosis, 8 cases (38.09%) indicated interstitial nephritis, 2 cases (9.52%) developed acute tubular necrosis, 2 cases (9.52%) revealed vacuolar degeneration inrenal tubular epithelium, 1 case had (4.76%) renal hemorrhage and in 3 cases (14.28%) renal autolysis was observable. In liver, 10 cases (47.61%) were affected to lymphocytic hepatitis, 5 cases (23.8%) possessed necrotic hepatitis, 6 cases (28.57%) of multifocal coagulative necrosis without inflammatory reaction and 3 cases (14.28%) with lymphocytic portal hepatitis were observed. In this assessment, 10 specimens (52.17%) of spleen tissues revealed necrosis and lymphatic tissues emptying and in 10 cases (100%) severe enteritis, which may be associated with IBR, were recorded. This study suggests based on lesions in several organs induced by IBR virus and real time PCR confirmation there is direct correlation between virus and lesions, and in order to obtain more reliable results of IBR infection the histopathological examination may be efficient.

Bovine herpesvirus 1abortion

While Bovine herpesvirus 1 (BoHV-1) has been known as a cause of bovine abortion for nearly 50 years, information is limited on the current prevalence of BoHV-1 abortion in the United Kingdom, or about the mode of virus dissemination to cause infection of the fetus. The present study aimed to investigate these issues by surveying the prevalence of BoHV-1 in abortion cases in the United Kingdom, and comparing diagnostic methods to determine which are most efficient in BoHV-1-induced abortion. Where BoHV-1 DNA was detected, viral load was compared in fetal tissues, using real-time polymerase chain reaction (PCR), supported by histopathology and immunohistochemistry (IHC) to investigate virus dissemination in bovine abortions. A total of 400 U.K. bovine abortion cases were studied; PCR detected BoHV-1 nucleic acids in 10 cases, suggestive histopathological lesions were observed in 8, and positive IHC staining was observed in 9. In routine diagnosis, BoHV-1 was identified in 2 of these cases, highlighting the utility of using molecular diagnostic tests such as real-time PCR to achieve high sensitivity in potentially autolyzed tissues. The study of different fetal samples showed the highest viral load in the liver, along with severe multifocal necrotic hepatitis, suggesting either a clear tropism of the virus for this organ or that it is the first location to be reached in the fetus. Presence of viral antigen in endothelial cells of the placenta, brain, or heart suggest a hematogenous spread of virus from placenta to the liver, through the umbilical vein, and then to the rest of the organs via fetal blood vessels.

Survey of nine abortifacient infectious agents in aborted bovine fetuses from dairy farms in Beijing, China, by PCR

Abortion in dairy cattle causes considerable economic losses to the dairy industry. Aborted fetuses and samples from the corresponding aborting dams from 12 dairy herds in Beijing were tested for 9 abortifacient infectious pathogens by PCR between 2008 and 2010. From a total of 80 abortion cases collected during this period, infectious agents were detected in 45 (56.3%) cases, 22 (48.9%) of which represented co-infections with two or three infectious agents. The detected pathogens included infectious bovine rhinotracheitis virus (36.3%) and Neospora caninum (31.3%), followed by bovine viral diarrhoea virus (7.5%), Brucella abortus (6.3%), Tritrichomonas foetus (5%) and Toxoplasma gondii (1.3%). Campylobacter fetus, Coxiella burnetii and Chlamydophila psittaci were not detected in any abortion case. Findings from this study indicated that infectious bovine rhinotracheitis virus and Neospora caninum were the main potential causes of abortions in Beijing dairy herds, whereas the bacterial pathogens were not, in contrast to reports from other countries. This is the first study to test nine abortifacient infectious agents by PCR at the same time, and it is also the first time to report the involvement of a variety of infectious agents in bovine abortion cases in China.