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Alexander J Trees - One of the best experts on this subject based on the ideXlab platform.

  • Risk factors for canine Neosporosis in farm and kennel dogs in southern Italy.
    Veterinary Parasitology, 2007
    Co-Authors: Paola Paradies, Alexander J Trees, Gioia Capelli, Gabriella Testini, Cinzia Cantacessi, Domenico Otranto
    Abstract:

    Neosporosis by Neospora caninum causes losses to livestock production through abortion in cattle while, in dogs, it induces neuromuscolar disease. This study investigated Neosporosis seroprevalence associated risk factors (including the seropositivity to leishmaniosis) in dogs of southern Italy, determined the prevalence of N. caninum oocyst shedding and examined the relationship between seroprevalence of Neosporosis in farm dogs and cattle. Using an inhibition ELISA, 20.9% of 306 dogs had percent inhibition values >10 (indicative of exposure) and farm dogs had a significantly (p < 0.001) higher seroprevalence than dogs in a rescue kennel. Whilst N. caninum seroprevalence was associated with increasing age in dogs (p 0.01) there was no association between seropositivity for N. caninum and for Leishmania infantum. Oocysts of N. caninum were not detected in faecal samples from 230 dogs including 160 farm dogs. The results indicated that Neosporosis infection is common in southern Italy both in dogs and in cattle and that dogs at higher risk of exposure are free-ranging ones living in farms. The lack of correlation between canine seroprevalence for N. caninum and L. infantum assumes a particular significance in an endemic area for leishmaniosis. # 2007 Published by Elsevier B.V.

  • Risk factors for canine Neosporosis in farm and kennel dogs in southern Italy.
    Veterinary Parasitology, 2007
    Co-Authors: Paola Paradies, Alexander J Trees, Gioia Capelli, Gabriella Testini, Cinzia Cantacessi, Domenico Otranto
    Abstract:

    Neosporosis by Neospora caninum causes losses to livestock production through abortion in cattle while, in dogs, it induces neuromuscolar disease. This study investigated Neosporosis seroprevalence associated risk factors (including the seropositivity to leishmaniosis) in dogs of southern Italy, determined the prevalence of N. caninum oocyst shedding and examined the relationship between seroprevalence of Neosporosis in farm dogs and cattle. Using an inhibition ELISA, 20.9% of 306 dogs had percent inhibition values >10 (indicative of exposure) and farm dogs had a significantly (p

  • Experimental Neosporosis in Pregnant Ewes and Their Offspring
    Veterinary Pathology, 1996
    Co-Authors: Milton M Mcallister, Alexander J Trees, David S Lindsay, R. H. Stobart
    Abstract:

    Six groups of six pregnant ewes each were inoculated with 170,000 or 1,700,000 tachyzoites of Neospora caninum on gestation day 65, 90, or 120. All ewes seroconverted, and none showed signs of illness other than abortion. Regardless of the inoculum dose, all ewes inoculated on gestation day 65 aborted; ewes inoculated on gestation day 90 aborted, gave birth to weak lambs, or gave birth to clinically normal lambs; and all ewes inoculated on gestation day 120 gave birth to clinically normal lambs. Using an immunohistological procedure that stains bradyzoites, we observed protozoal cysts in brains of 11 of 29 (38%) aborted fetuses, in one of four (25%) weak lambs, and in seven of 18 (39%) clinically normal lambs. Cysts were not observed in extraneural tissues from two clinically normal lambs that had cysts in the brain. No evidence of infection was observed in tissues of five ewes examined using an immunohistological procedure that stains N. caninum tachyzoites and bradyzoites. Multifocal nonsuppurative encephalitis was observed in 46 of 51 (90%) aborted, weak, or clinically normal lambs. Cerebral necrosis, dystrophic mineralization, and meningitis were also commonly identified in live and aborted lambs (even when severely autolyzed). Nonsuppurative, necrotizing placentitis was observed in 15 of 17 (88%) placentas. Nonsuppurative myositis was common in fetuses but not in live lambs. Inflammation occurred less frequently in liver and lung. Clinical and pathological features of Neosporosis in sheep closely resemble those of bovine Neosporosis and ovine toxoplasmosis. Although abortion caused by naturally occurring Neosporosis in sheep has not been reported, diagnosticians should carefully distinguish between Neosporosis and toxoplasmosis in cases of ovine protozoal abortion unless future investigations exclude the likelihood of naturally acquired Neosporosis in sheep.

  • characterization of the first european isolate of neospora caninum dubey carpenter speer topper and uggla
    Parasitology, 1995
    Co-Authors: J S Barber, O. J. M. Holmdahl, Arvid Uggla, M R Owen, Alexander J Trees
    Abstract:

    : Neospora caninum is an apicomplexan, protozoan parasite, which causes severe disease in dogs and cattle. It has previously been isolated only in the United States. A 5-week-old Boxer pup with a progressive hindlimb paresis was diagnosed as suffering from Neosporosis on the basis of clinical signs and the presence of anti-Neospora antibodies in it, 2 litter-mates and its dam. Despite treatment with sulphonamides, the pup was euthanased 3 days later. The diagnosis of Neosporosis was confirmed by immunohistochemical examination of muscle and CNS tissue sections from the pup. Parasites were isolated into Vero cell culture from the cerebrum, and confirmed as Neospora caninum by immunofluorescence with specific antibody, tachyzoite ultrastructure and 16S-like ribosomal RNA sequences. This isolate (designated NC-Liverpool) has been continuously passaged every 7-10 days. Its growth characteristics, ultrastructure and antigenic profile, as revealed by immunoblotting, have revealed no major differences from the American NC-1 isolate. Furthermore, no difference was seen when comparing the sequences of 16S-like ribosomal RNA and the ITS1 region of the two isolates.

Jan Slapeta - One of the best experts on this subject based on the ideXlab platform.

  • neonatal Neosporosis in a 2 week old bernese mountain dog infected with multiple neospora caninum strains based on ms10 microsatellite analysis
    Veterinary Parasitology, 2016
    Co-Authors: Rodrigo Prandini Da Costa Reis, Robin Crisman, Margie Roser, R Malik, Jan Slapeta
    Abstract:

    Neonatal Neosporosis is a challenging disease to diagnose in neonatal and young puppies because the first signs of this condition may not be strongly suggestive of an infectious aetiology. Within two weeks of birth, three of four pups died with a subacute clinical course, some with dyspnea, some with diarrhoea and some with neurologic signs. Neosporosis was diagnosed post-mortem, but only after microscopic examination of tissues collected at necropsy. Histological findings consisted of (i) necrotizing, diffuse interstitial pneumonia associated with intralesional protozoa and (ii) necrotizing multifocal myocarditis with mineralization and intralesional protozoa. No significant alterations were found in the cerebrum or cerebellum (spinal cord was not examined). Immunohistochemistry confirmed protozoal stages and cysts were Neospora caninum. Immunohistochemistry for Toxoplasma gondii was negative. Lung and heart were the most severely affected tissues with large numbers of free zoites, BAG5 positive bradyzoites and tissue cysts of N. caninum further confirmed by N. caninum-specific quantitative real-time PCR. One affected pup which displayed knuckling, ataxia and diarrhoea were treated with trimethoprim sulfadiazine and clindamycin, and made a complete recovery. This surviving pup (at 8 weeks-of-age) and dam were both positive for N. caninum antibody (reciprocal titres 4096 and 256, respectively). Three other intact bitches on the same property were seropositive for N. caninum, suggesting horizontal transmission and a common source of infection, possibly due to consumption of infected meat. Analysis using microsatellite-10 (MS10) demonstrated that multiple strains of N. caninum were present. It was likely that all MS10 N. caninum strains were transplacentally transmitted from dam to pups. This is the first time that multiple N. caninum strains have been demonstrated to be vertically transmitted in dogs. N. caninum should be considered in the differential diagnosis for acute to subacute death in neonatal pups even when neurological signs suggestive of Neosporosis are absent.

  • a review of Neosporosis and pathologic findings of neospora caninum infection in wildlife
    International journal for parasitology. Parasites and wildlife, 2015
    Co-Authors: Shannon L Donahoe, Scott A. Lindsay, Mark B Krockenberger, David N Phalen, Jan Slapeta
    Abstract:

    Neospora caninum is an apicomplexan parasite that is the etiologic agent of Neosporosis, a devastating infectious disease regarded as a major cause of reproductive loss in cattle and neuromuscular disease in dogs worldwide. This protozoan pathogen is maintained in the environment by a heteroxenous life cycle that involves a definitive canid host and a wide range of intermediate hosts. In recent years, a number of wildlife species have been investigated for their possible involvement in the N. caninum life cycle and many have been implicated as intermediate hosts. However, in many instances these studies have utilized serological and molecular techniques to detect infection in clinically normal animals, and investigation of possible associated morbidity, mortality, and pathology has been neglected. As such, the occurrence and importance of Neospora-associated disease in wildlife species are unknown. In order to improve our understanding of the significance of N. caninum infection in nondomestic species, the present review provides an up-to-date summary of clinical Neosporosis and N. caninum-associated pathologic lesions in naturally and experimentally infected wildlife species. We provide a list of all free-ranging and captive wildlife species identified with N. caninum infection to date using currently available diagnostic tools. The advantages and disadvantages of diagnostic methods in wildlife are addressed in order to recommend optimal diagnosis of confirming N. caninum infection and Neosporosis in nondomestic species. Although current data would suggest that N. caninum infection does not adversely impact wildlife populations, there is a need for greater international uniformity in the diagnosis of N. caninum infection and Neosporosis in nondomestic species in order to assess the true consequences of parasite infection.

  • implications of wild dog ecology on the sylvatic and domestic life cycle of neospora caninum in australia
    Veterinary Journal, 2011
    Co-Authors: Jessica S King, David Jenkins, John Ellis, Peter Fleming, P A Windsor, Jan Slapeta
    Abstract:

    Abstract Neospora caninum is transmitted either transplacentally or horizontally by ingestion of tissue cysts present in tissues or oocysts shed by dogs. Neosporosis is a significant disease, causing cattle abortion at 5–7 months of pregnancy. Infected cows may remain infective for life transmitting the infection in several consecutive or non-consecutive pregnancies. A great deal is known about the epidemiology of Neosporosis, although only limited information is available on the main routes of horizontal transmission. In Australia, the presence of the dingo as the top-order predator suggests a potential sylvatic route of transmission between dingoes and as yet unknown native wildlife in addition to the domestic route via dogs with access to infected tissue on farms. This review article critically evaluates the overlap between the domestic and sylvatic routes, taking into account canine ecology, and summarises current understanding of the transmission of N. caninum to provide a foundation for epidemiologists, farmers and conservation biologists dealing with Neosporosis and wild dog control programs.

  • Extensive production of Neospora caninum tissue cysts in a carnivorous marsupial succumbing to experimental Neosporosis
    Veterinary Research, 2011
    Co-Authors: Jessica S King, John Ellis, Bronwyn M. Mcallan, Derek Spielman, Scott A. Lindsay, Lada Hůrková-hofmannová, Ashlie Hartigan, Sarwat Al-qassab, Jan Slapeta
    Abstract:

    Experimental infections of Sminthopsis crassicaudata, the fat-tailed dunnart, a carnivorous marsupial widely distributed throughout the arid and semi-arid zones of Australia, show that this species can act as an intermediate host for Neospora caninum. In contrast to existing models that develop relatively few N. caninum tissue cysts, dunnarts offer a new animal model in which active Neosporosis is dominated by tissue cyst production. The results provide evidence for a sylvatic life cycle of N. caninum in Australia between marsupials and wild dogs. It establishes the foundation for an investigation of the impact and costs of Neosporosis to wildlife.

Jitender P. Dubey - One of the best experts on this subject based on the ideXlab platform.

  • Histologically, immunohistochemically, ultrastructurally, and molecularly confirmed Neosporosis abortion in an aborted equine fetus.
    Veterinary Parasitology, 2019
    Co-Authors: Joseph A. Anderson, Daniel K Howe, Derron A. Alves, Camila K. Cerqueira-cézar, Andressa F. Da Silva, Fernando Henrique Antunes Murata, Jamie K. Norris, Jitender P. Dubey
    Abstract:

    Abstract Neosporosis is a common cause of abortion in cattle worldwide but is rare in horses. Here, the first case of histologically, ultrastructurally, immunohistochemically, and molecularly confirmed equine abortion caused by Neosporosis is reported. Samples of lung, heart, liver, skeletal muscle, tongue, brain, and the placenta from a female fetus aborted at 280 days of gestation were fixed in formalin and submitted for diagnosis. Histologically, there was disseminated Neosporosis with severe lesions in lungs, liver and the heart. Protozoal tachyzoites in all tissues reacted with polyclonal anti-Neospora caninum rabbit antibodies. Transmission electron microscopic observation on lung tissue revealed tachyzoites consistent with Neospora, including many rhoptries. Polymerase-chain reaction (PCR) using primers designed to amplify the rRNA gene internal transcribed spacer 1 (ITS1) of the Sarcocystidae was performed on DNA extracted from fetal tissues. Comparison of the ITS1 amplified from the foal tissue to sequences available in GenBank revealed 100% sequence identity to the ITS1 from three isolates of Neospora hughesi.

  • All about Neosporosis in Brazil.
    Revista Brasileira de Parasitologia Veterinária, 2017
    Co-Authors: Camila K. Cerqueira-cézar, Jitender P. Dubey, Rafael Calero-bernal, Solange Maria Gennari
    Abstract:

    Neospora caninum is protozoan parasite with domestic and wild dogs, coyotes and grey wolves as the definitive hosts and many warm-blooded animals as intermediate hosts. It was cultivated and named in 1988. Neosporosis is a major disease of cattle and has no public health significance. Since 1990's N. caninum has emerged as a major cause of abortion in cattle worldwide, including in Brazil. N. caninum also causes clinical infections in several other animal species. Considerable progress has been made in understanding the biology of N. caninum and there are more than 200 papers on this subject from Brazil. However, most of the reports on Neosporosis from Brazil are serological surveys. Overall, little is known of clinical Neosporosis in Brazil, particularly cattle. The few reports pertain to sporadic cases of abortion with no information on epidemics or storms of abortion. The objective of the present review is to summarize all reports from Brazil and suggest topic for further research, including prevalence of N. caninum oocysts in soil or in canine feces, and determining if there are additional definitive hosts, other than the domestic dog. There is need for a national survey in cattle using defined parameters. Future researches should focus on molecular characterization of N. caninum strains, possibility of vaccine production and relationship between wildlife and livestock epidemiology.

  • Neosporosis in Animals
    2017
    Co-Authors: Jitender P. Dubey, Andrew Hemphill, Rafael Calero-bernal, Gereon Schares
    Abstract:

    In the 1980’s a neuromuscular syndrome of dogs simulating toxoplasmosis was recognized. In 1988, a new genus, Neospora, and the type species, Neospora caninum, were named, cultivated in vitro, and differentiated from Toxoplasma gondii. A year later, N. caninum was identified as an etiological agent for bovine abortions. Considerable progress in understanding the biology of Neosporosis has been made in the last 30 years, resulting in more than 2000 scientific publications. The economic importance of abortion in cattle, and the availability of knowledge, reagents, and technology used to study toxoplasmosis, have contributed to the rapid progress in understanding the biology of Neosporosis. Whole genome sequencing of N. caninum confirmed close similarities between N. caninum and T. gondii. However, these 2 protozoans are biologically different: N. caninum causes a major disease in cattle, and canids are its definitive hosts, whereas toxoplasmosis is a major public health problem and felids are its definitive host. Both parasites have wide host range. Here we summarize information on the biology of Neosporosis, starting with a chapter 1 on the historical background. Subsequent chapters deal with general aspects of the biology of N. caninum (chapter 2), techniques (chapter 3), and the disease caused by this parasite in cattle (chapter 4), dogs (chapter 5), and all other animals including primates and humans (chapters 6-18). Abortion is a worldwide problem in livestock industry accounting for annual economical losses of billions of dollars, and N. caninum is a major cause of it. Neosporosis causes abortion in both dairy and beef cattle. Abortions not only occur in cattle that have been exposed recently but also in chronically infected cattle, which poses a major challenge for vaccine development. There is no effective vaccine or therapy to eliminate N. caninum in cattle, but progress is being made. In this book, we provide an up to date account of structure, biology, clinical disease, diagnosis, epidemiology, treatment, attempts at immunoprophylaxis, and control in all hosts. There are 175 illustrations on the life cycle, structure of parasitic stages, and of lesions. More than 2100 references are cited. It is hoped that this book will be useful to biologists, veterinarians, and researchers.

  • Diagnosis of bovine Neosporosis
    Veterinary Parasitology, 2006
    Co-Authors: Jitender P. Dubey, Gereon Schares
    Abstract:

    The protozoan parasite Neospora caninum is a major cause of abortion in cattle. The diagnosis of Neosporosis-associated mortality and abortion in cattle is difficult. In the present paper we review histologic, serologic, immunohistochemical, and molecular methods for dignosis of bovine Neosporosis. Although not a routine method of diagnosis, methods to isolate viable N. caninum from bovine tissues are also reviewed.

  • Cutaneous Neosporosis during treatment of pemphigus foliaceus in a dog.
    Journal of the American Animal Hospital Association, 2002
    Co-Authors: Laura Ordeix, Jitender P. Dubey, Albert Lloret, Dolors Fondevila, Lluís Ferrer, Alessandra Fondati
    Abstract:

    A 4-year-old, intact male rottweiler was presented with a 10-day history of papulonodular dermatitis. At the time of presentation, the dog was receiving prednisone and azathioprine to treat pemphigus foliaceus. Cutaneous Neosporosis was diagnosed by immunohistochemistry on skin biopsy specimens and a high serum antibody titer to Neospora caninum by Neospora agglutination test. Electron microscopy examination of skin specimens further supported the diagnosis. Clindamycin therapy, together with withdrawal of immunosuppressive medication, resulted in prolonged clinical remission. This report documents cutaneous Neosporosis in an adult dog and suggests that immunosuppressive therapy might be a predisposing factor.

Gregory P Keefe - One of the best experts on this subject based on the ideXlab platform.

  • direct production losses and treatment costs from bovine viral diarrhoea virus bovine leukosis virus mycobacterium avium subspecies paratuberculosis and neospora caninum
    Preventive Veterinary Medicine, 2002
    Co-Authors: John A Vanleeuwen, Alfons Weersink, Gregory P Keefe
    Abstract:

    Abstract Our purpose was to determine direct production losses (milk loss, premature voluntary culling and reduced slaughter value, mortality loss, and abortion and reproductive loss) and treatment costs (veterinary services, medication cost, and extra farm labour cost) due to four infectious diseases in the Maritime provinces of Canada: bovine viral diarrhoea (BVD), enzootic bovine leukosis (EBL), Johne’s Disease (JD), and Neosporosis. We used a partial-budget model, and incorporated risk and sensitivity analyses to identify the effects of uncertainty on costs. Total annual costs for an average, infected, 50 cow herd were: JD$ 2472; BVD$ 2421; Neosporosis $ 2304; EBL$ 806. The stochastic nature of the proportion of infected herds and prevalence of infection within a herd were used to estimate probability distributions for these ex post costs. For all diseases, these distributions were right skewed. A sensitivity analysis showed the largest effect on costs was due to milk yield effects. For example, changing milk production loss from 0 to 5% for BVD increased the costs for the disease by 266%.

Patricia A. Conrad - One of the best experts on this subject based on the ideXlab platform.

  • immune responses to neospora caninum and prospects for vaccination
    Trends in Parasitology, 2002
    Co-Authors: Elisabeth A Innes, A G Andrianarivo, Camilla Bjorkman, D J L Williams, Patricia A. Conrad
    Abstract:

    Developing an effective vaccine against Neosporosis presents several interesting challenges. The parasite is spread efficiently from mother to foetus over several generations, and naturally infected cattle do not appear to develop adequate protective immunity. Modulation of the immune response during pregnancy favours parasite survival and multiplication. However, induction of pro-inflammatory responses that are thought to be protective against Neospora caninum would be detrimental to the pregnancy. So, is vaccination a feasible option to control the disease? This article discusses some of these issues and reports on the progress towards a vaccine for Neosporosis.

  • Neosporosis in cattle
    Animal Reproduction Science, 2000
    Co-Authors: Mark L Anderson, A G Andrianarivo, Patricia A. Conrad
    Abstract:

    Abstract During the past decade, Neospora caninum infection has emerged as an important reproductive disease in cattle throughout the world. Abortion, occurring during the middle of gestation, is the primary clinical sign of the infection in cattle. Surveys in several countries from three continents have identified N. caninum infection as the major diagnosed cause of bovine abortion. Both endemic and epidemic patterns of abortion may occur in herds. An important feature of this disease is that the protozoan parasite is maintained in cattle as a chronic infection which can be passed on to the fetus during pregnancy. Two methods for the transmission of the infection in cattle have been proposed and are the subject of current investigations. Horizontal transmission utilizes a two-host life cycle whereby the cow is infected from ingestion of coccidial oocyst stages shed by the definitive host. Experimental infections have confirmed that the dog is a definitive host for the parasite. There is epidemiological evidence that the dog has a role in the prevalence of the infection but, as yet, no confirmation that the dog is the source for natural infections in cattle. Vertical transplacental transmission of the infection is an important route of infection in many herds. Vertical transmission occurs because fetal infection frequently does not result in abortion but rather the fetus survives to be a persistently infected animal. A heifer calf that is born congenitally infected is capable of transmitting the infection to the next generation when she becomes pregnant, thus maintaining the infection in the herd. The clinical outcome of transplacental fetal infection with N. caninum is likely determined by maternal and fetal immune responses which involve humoral, and most importantly, cell-mediated immune factors. The diagnosis of the infection is assisted through histopathology and immunohistochemical examination of aborted fetuses and serologic testing of cattle for evidence of infection. Several types of serologic tests, based on the use of culture-derived organisms or recombinant N. caninum antigens are available. There are no proven control methods for the prevention or treatment of Neosporosis. Suggested control measures focus on programs to reduce the number of congenitally infected animals retained in the herd and to minimize the opportunity for postnatal transmission from the environment.

  • Neosporosis as a cause of equine protozoal myeloencephalitis
    Journal of the American Veterinary Medical Association, 1996
    Co-Authors: Antoinette E. Marsh, Bradd C. Barr, John E Madigan, Jeffrey Lakritz, Robert W. Nordhausen, Patricia A. Conrad
    Abstract:

    Neosporosis was diagnosed in an 11-year-old Quarter Horse gelding with clinical signs and diagnostic test results compatible with equine protozoal myeloencephalitis (EPM). Presumptive postmortem diagnosis of EPM attributable to Sarcocystis neurona infection is generally made on the basis of detecting an antibody titer to S neurona in the CSF or characteristic histologic lesions, even when parasites have not been specifically identified. Neosporosis was confirmed in the horse described here by use of immunohistochemical examination, in vitro culturing, and ultrastructural and molecular characterization of parasites from infected tissues. Antibody testing of serum and CSF samples indicated that Neospora-specific anti-bodies can react with S neurona proteins on western blot analysis. The confirmation that Neosporosis in horses can mimic EPM emphasizes the need to broaden the etiologic definition of EPM beyond infections exclusively attributable to S neurona.