Neospora-like protozoal infections associated with bovine abortions

Eighty bovine fetuses with presumed protozoal infections from a previous 2-year retrospective study were examined by immunohistochemistry using antisera against Neospora caninum. In 66 (83%) of the fetuses, protozoa were found that reacted positively with anti-N. caninum sera. In three (4%) additional fetuses, protozoa identified as Sarcocystis species did not react, and in two fetuses (3%) single protozoal clusters were found only in hematoxylin and eosin-stained slides. A group of 20 fetuses were chosen for further evaluation. They included 14 fetuses from the first group of 80 fetuses plus six additional fetuses that had large numbers of protozoa in the fetal brain. The 20 fetuses were examined immunohistochemically with antisera to N. caninum, Hammondia hammondi, and Toxoplasma gondii. Protozoa from 3/20 fetuses, identified as Sarcocystis species, failed to react with any antisera. In 16/20 fetuses protozoa reacted positively to antisera against N. caninum, and in most cases reacted to H. hammondi, and weakly to one or more of the antisera against T. gondii. Thick-walled protozoal tissue cysts were found in the brain of four of these 16 fetuses by transmission electron microscopy. The cyst wall morphology was comparable to N. caninum. The results suggested that a single protozoal parasite of unknown identity was responsible for most of the bovine abortions. By immunohistochemistry, the unknown protozoon reacted most strongly and consistently to N. caninum antisera, but was antigenically distinct from N. caninum. Ultrastructurally, tissue cysts found in four fetuses most closely resembled Neospora caninum.     

Bovine fetal encephalitis and myocarditis associated with protozoal infections

Bovine fetuses submitted to the California Veterinary Diagnostic Laboratory System were evaluated during a 2-year period (1987 to 1989) for the presence of multifocal necrotizing nonsuppurative encephalitis, nonsuppurative myocarditis, or tissue protozoa. Eighty-two of 445 (18%) fetuses submitted met these histologic criteria. Fetuses were from 54 dairy and two beef herds located throughout the state. In 17 fetuses (21%) protozoa were found in fetal tissues. Protozoa were found in brain parenchyma of ten fetuses (12%), in endothelial cells in four fetuses (5%), in cardiac myofibers in one fetus (1%), and were associated with endothelial cells in two fetuses (2%). In most fetuses there were no significant gross pathologic findings other than autolysis. While aborted fetuses were from 3 to 9 months gestation, the majority were between 5 and 7 months gestation. They were submitted year round, but more were seen in the fall and winter months. Additional salient histologic features included portal nonsuppurative hepatitis, focal hepatic inflammation and necrosis, and focal nonsuppurative myositis. Nonsuppurative inflammation was also found in decreasing frequency, in the adrenal medulla, kidney, mesentery or abdominal fat, placenta, and lung. In two fetuses (Nos. 1 and 2), the location and morphology of the protozoa were compatible with Sarcocystis spp. The identity of protozoa in the remaining 15 fetuses is unknown. The histopathologic changes in these 82 fetuses and the presence of protozoa in 21% of the fetuses suggest these abortions are due to fetal protozoal infections.     

Myelitis associated with protozoal infection in newborn calves

Four newborn calves from different herds were examined because of recumbency and inability to rise. Abnormal physical findings were confined to the nervous and/or musculoskeletal systems. Because of poor prognosis, all calves were euthanatized and necropsied. The histopathologic findings were multifocal lymphocytic myelitis, meningitis, and encephalitis associated with protozoal cysts.     

Neospora-like protozoan infection as a major cause of abortion in California dairy cattle

Ninety-five aborted bovine fetuses received from California dairies over a 4.5-year period had histologic lesions of focal encephalitis. Protozoa that reacted with Neospora caninum antiserum were detected in the brain of 88 of these fetuses and in the heart of 1 fetus. Sarcocystis spp schizonts were seen in the vascular endothelium of 1 fetus. It was concluded that a Neospora-like cyst-forming coccidian may be a major cause of abortion in California dairy cattle.     

山羊流产病因调查

本县北山地区有巴扎、加定两乡 ,共 1 4个行政村 (其中巴扎 8个、加定 6个 ) ,是本县山羊生产基地。多年来 ,山羊流产一直是困扰该地区乃至我县畜牧业发展的重要原因。笔者于 1 998年 3月流产发生期间 ,对部分流产山羊进行了布病、衣原体和弓形体的血清学诊断。报告如下。1　流行病学1 .1　自然生态　北山地区为林、牧、农结合地区。有高山、中山、河谷 ,海拔高度在 2 1 0 0～ 42 0 0 m,年平均气温 - 2℃～ 4℃ ,降水量 50 0～ 6 0 0 mm,辖区内牲畜严重超载 ,1 998年底 ,二乡共存栏绵山羊 3 .54万只 ,其中山羊占 6 9% ,适龄母羊比例为 42 .7…     

Toxoplasma gondii-induced abortion in dairy goats

Three of 8 goats on a Maryland farm aborted or had dystocia associated with toxoplasmosis during the winter of 1984. Doe 1 aborted a decomposed fetus 30 days before term. Modified agglutination test (MAT) antibody titers against Toxoplasma gondii were found in pleural fluid of the fetus (1:1,024) and in serum of doe (1:4,096 at 31 days after abortion). Doe 2 aborted a fetus 5 days before term; MAT antibody was found in the pleural fluid of the fetus (1:16,384) and in the doe's serum (1:4,096 on the day of abortion). Placenta from both does had foci of necrosis characteristic of toxoplasmosis, and T gondii was identified in lesions. Doe 3 had dystocia 7 days before term and a partially decomposed fetus was delivered by cesarian section; MAT was found in pleural fluid of the fetus (1:1,024) and in serum from the doe (1:4,096 on the day of abortion). Focal gliosis and calcification were seen in brain specimens from 2 of the 3 fetuses. None of the does produced milk after abortion. Two other does (No. 4 and 5) delivered apparently healthy kids transplacentally infected with T gondii; MAT in serum of both does was 1:4,096. Doe 4 delivered 3 kids; MAT titer in a serum from each kid 38 days after birth was 1:16,384. Doe 5 delivered 1 kid with a serum MAT titer of 1:1,024 at 38 days after birth. The 3 remaining does had MAT titers of 1:256, 1:16, and 1:16, and all delivered healthy kids. Epizootiologic evidence suggested that the does acquired T gondii infection from oocysts passed in feces of domestic cats on the farm. The MAT titers of 4 cats on the farm were 1:65,356; 1:1,024; 1:16; and 1:1,024.     

Prevalence of microorganisms associated with udder infections in dairy goats on small-scale farms in Kenya

Six hundred and thirty clinically-normal milk samples from dairy goat flocks comprising a mixed population of German Alpine, Toggenburg, Saanen and Galla crosses were examined over a 3-month period to determine the prevalence of bacterial organisms. Bacteria were isolated in 28.7% of the milk samples (181/630) either singly (92.8%) or in combination (7.2%). The most prevalent bacterial organisms were Staphylococcus spp. (60.3%), followed by Micrococcus spp. (17.7%), Acinetobacter spp. (5%), Actinomyces spp. (5%) and Streptococcus spp. (1.1%). The Staphylococcus spp. were mainly coagulase negative (64.3%). Coagulase-negative staphylococci and coagulase-positive staphylococci accounted for 37.5% and 22.7% respectively of the total bacteria isolated. The isolation of bacteria, some of which are important in clinical and subclinical mastitis, in apparently normal caprine milk, indicates that particular attention should be given to the management of these dairy goat flocks in order to avoid the development of cases of clinical mastitis.     

Zoonotic implications of the swine-transmitted protozoal infections

Pig production is an important part of the economy in many countries. Domestic and wild pigs (Sus scrofa) are susceptible to a wide range of infectious and parasitic diseases. Some of these diseases are specifically limited to pigs while some of the other diseases are shared with other species of wildlife and domestic livestock. As the numbers and geographic distribution of wild and domestic swines continue to increase, it is certain that the number of contacts between these swines and domestic livestock will also increase, as will the probability of human exposure to the parasites of swine directly or indirectly. Here, we will discuss the protozoal infections of pigs, which have the potential to infect humans and provide reasonable risk assessment for zoonotic transmission.     

Bovine abortion associated with Anaplasma marginale.

During the period from June 1974 to June 1975, five bovine fetuses between seven to nine months old were received for necropsy from four different counties of the S. Paulo State, Brazil. All of them were from brucellosis-free herds. Necropsy revealed slight liver enlargement generally accompanied by capsular petechial hemorrhages. Enlargement and congestion of the spleen, epicardial and endocardial petechiae were present in three fetuses and one of them had lungs with some hemorrhagic lobules. Cardiac blood films of all the fetuses stained by the Pappenheim's panoptic method showed Anaplasma marginale in two to 20% of red corpuscles. When stained with acridine orange and immunofluorescent methods blood films of the first fetus specifically showed A. marginale.     

Toxoplasma infection and abortion in dairy goats

Summary Serological investigation by the indirect haemagglutination test forToxoplasma antibodies was carried out in a flock of dairy goats. Antibody titres ranging from 1:4 to 1:1,024 were found in 34% of 371 apparently healthy animals. High antibody titres of 1:256 suggestive of recent infection were noted in 18 (4.9%) animals including 13 nannies. The occurrence of a number of non-brucella abortions associated with high serological titres and the isolation of the parasite from the brain tissues of an aborted foetus suggestedToxoplasma as a probable aetiologic factor. Sera having significant levels of haemagglutinating antibodies (1:128) were also found positive to the card agglutination test. Epidemiological aspects and the public health potential of subclinical toxoplasmosis in dairy goats are discussed.

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Infecciones Y Abortos En Cabras Lecheras Debido AToxoplasma

Resumen Se realizaron investigaciones serológicas de toxoplasmosis mediante la prueba indirecta de hemaglutinación en un rebaño de cabras lecheras. Se encontraron títulos de 1:4 a 1:1024 en 34% de 371 animales aparentemente sanos. Títulos de 1:256 sugestivos de infecciones recientes, se encontraron en 18 (4.9%) animales, incluyendo 13 hembras paridas. La ocurrencia de un significativo número de abortos no asociados con brucela, títulos serológicos altos de toxoplasmosis y el aislamiento del parásito del cerebro de fetos abortados, sugiere que eltoxoplasma es el factor etiológico más importante. Se discuten aspectos epidemiológicos de importantcia para la salud pública, relacionados con el potencial de la toxoplasmosis (subclínica) en cabras lecheras.

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Toxoplasmose Et Avortement Chez Les Chevres Latiteres

Résumé Des investigations sérologiques par la méthode de l'agglutination indirecte pour rechercher des anticorps toxoplasmiques ont été faites sur un troupeau de chèvres laitières. Des anticorps ont été mis en évidence chez 34 p.100 des 371 animaux apparemment sains à des titres allant de 1:4 à 1:1024. Des titres élevés d'anticorps atteignant 1:256 ont été relevés chez 18 (soit 4,9 p.100) des animaux comprenant 13 chèvres, ce qui fait penser à une infection récente.L'existence de nombre d'avortements non-brucelliques associés avec des titres sérologiques élevés et l'isolement du parasite des tittus cérébraux d'un foetus avorté suggerent que les Toxoplasmes en ont probablement été le facteur étiologique. Des sérums ayant des taux significativement élevés d'anticorps agglutinants (1:128) ont également été reconnus comme positifs par le test d'agglutination en EAT. Les aspects épidémiologiques et le danger potentiel pour l'homme de ces cas subcliniques de toxoplasmose chez les chèvres laitières sont discutés.

     

Neurological diseases of ruminant livestock in Australia. III: bacterial and protozoal infections

Bacteria (including chlamydia) and protozoa can produce neurological disease in Australian ruminant livestock and the nature of the inflammatory and neuroparenchymal response is often suggestive of a particular aetiological agent. An overview of the clinicopathological features of infectious disease affecting the central nervous system (CNS) is followed by a discussion of important bacterial and protozoal infections in Australia. Each infectious disease is discussed in terms of classification and pathogenesis linked to clinical signs and gross and microscopic findings. The literature review is restricted to infectious conditions causing CNS disease in Australia. Sources include the Australian Veterinary Journal (over 50 years of articles), the quarterly newsletter of the National Animal Health Surveillance System and the Animal Health Surveillance Quarterly.