Potomac Horse Fever

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Enzyme linked immunosorbent assay for Potomac horse fever disease

Enzyme linked immunosorbent assay for Potomac horse fever disease

The results obtained suggest that the following criteria can be used for the diagnosis of Potomac horse fever or determination of recent exposure to the ehrlichial antigen by this ELISA:[r]

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Comparison of PCR and culture to the indirect fluorescent antibody test for diagnosis of Potomac horse fever

Comparison of PCR and culture to the indirect fluorescent antibody test for diagnosis of Potomac horse fever

Ehrlichia risticii is an obligatory intracellular bacterium in the family Rickettsiaceae (9, 21). E. risticii is the causative agent of Potomac horse fever (PHF), characterized by anorexia, fe- ver, depression, diarrhea, leukopenia, dehydration, and lami- nitis (9, 18, 21). Serologic evidence of infection is found throughout the United States, Canada, and Europe (7, 23, 27). However, culture for E. risticii was only done with specimens from horses residing in Maryland (5, 8, 21), Ohio (4), and Kentucky (4, 24). Experimentally infected horses develop im- munoglobulin M and immunoglobulin G antibodies against E. risticii (15, 16, 18), and therefore, an indirect fluorescent-anti- body (IFA) test has been widely used for diagnosis (23). The IFA test titer, however, does not distinguish between present and past infection or vaccination. Bacterins made of the type strain of E. risticii are available from three commercial sources. The efficacies of vaccines in the field are perceived to be marginal (13). In agreement with this perception, E. risticii has been isolated from sick horses which had been vaccinated (4, 26). Although, rising IFA test titers with accompanying clinical signs suggest active infection, an IFA test at a single time point is useless in diagnosing PHF in vaccinated horses. Seroepide- miologic studies reported high incidences of seropositive horses without clinical signs (1, 6, 10, 17, 19). A recent com- parative serologic study of Californian horses for PHF suggests that this might be partially due to a high incidence of false- positive IFA test results in some laboratories (12). Therefore, a test which directly detects the presence of ehrlichial organ- isms in clinical specimens is desirable. A one-step PCR which detects unknown target DNA of E. risticii was previously used to detect E. risticii in the blood and feces of two experimentally
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Association of Deficiency in Antibody Response to Vaccine and Heterogeneity of Ehrlichia risticii Strains with Potomac Horse Fever Vaccine Failure in Horses

Association of Deficiency in Antibody Response to Vaccine and Heterogeneity of Ehrlichia risticii Strains with Potomac Horse Fever Vaccine Failure in Horses

Ehrlichia risticii is the causative agent of Potomac horse fever (PHF), which continues to be an important disease of horses. Commercial inactivated whole-cell vaccines are regularly used for immunization of horses against the disease. However, PHF is occurring in large numbers of horses in spite of vaccination. In a limited study, 43 confirmed cases of PHF occurred between the 1994 and 1996 seasons; of these, 38 (89%) were in horses that had been vaccinated for the respective season, thereby clearly indicating vaccine failure. A field study of horses vaccinated with two PHF vaccines indicated a poor antibody response, as determined by immunofluorescence assay (IFA) titers. In a majority of horses, the final antibody titer ranged between 40 and 1,280, in spite of repeated vaccinations. None of the vaccinated horses developed in vitro neutralizing antibody in their sera. Similarly, one horse experimentally vaccinated three times with one of the vaccines showed a poor antibody response, with final IFA titers between 80 and 160. The horse did not develop in vitro neutralizing antibody or antibody against the 50/85-kDa strain-specific antigen (SSA), which is the protective antigen of the original strain, 25-D, and the variant strain of our laboratory, strain 90-12. Upon challenge infection with the 90-12 strain, the horse showed clinical signs of the disease. The horse developed neutralizing antibody and antibody to the 50/85-kDa SSA following the infection. Studies of the new E. risticii isolates from the field cases indicated that they were heterogeneous among themselves and showed differences from the 25-D and 90-12 strains as determined by IFA reactivity pattern, DNA amplification finger printing profile, and in vitro neutralization activity. Most importantly, the molecular sizes of the SSA of these isolates varied, ranging from 48 to 85 kDa. These studies suggest that the deficiency in the antibody response to the PHF vaccines and the heterogeneity of E. risticii isolates may be associated with the vaccine failure.
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Helminthic Transmission and Isolation of Ehrlichia risticii, the Causative Agent of Potomac Horse Fever, by Using Trematode Stages  from Freshwater Stream Snails

Helminthic Transmission and Isolation of Ehrlichia risticii, the Causative Agent of Potomac Horse Fever, by Using Trematode Stages from Freshwater Stream Snails

Ehrlichia risticii is the causative agent of Potomac horse fever (PHF), a febrile colitis of horses reported in North America and Europe (17, 20). The mode of transmission of E. risticii infection and the reservoir of infection have remained unknown. Other ehrlichial agents are tick transmitted; how- ever, evidence of tick transmission has not been found for E. risticii (4, 8, 19). Recent identification of a close genetic rela- tionship between E. risticii and Neorickettsia helminthoeca iso- lated from a fluke (Nanophyetus salmincola) suggested that the vector of E. risticii might be a trematode (12, 15). We demon- strated the presence of E. risticii genes in virgulate cercariae from operculate freshwater snails from an area of northern California where PHF is prevalent (2, 13). On the basis of these findings, we formed the hypothesis that snails and their trematodes are involved in the life cycle of E. risticii. Here we report the biological, ultrastructural, and genetic identification of E. risticii in trematode stages collected from freshwater snails and helminthic transmission of E. risticii to horses.
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Diagnostic application of polymerase chain reaction for detection of Ehrlichia risticii in equine monocytic ehrlichiosis (Potomac horse fever)

Diagnostic application of polymerase chain reaction for detection of Ehrlichia risticii in equine monocytic ehrlichiosis (Potomac horse fever)

Ethidium bromide-stained agarose gels containing PCRamplified products from four clinical specimens lanes 1 to 4 collected from experimentally infected horses and processed by the rapid [r]

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Experimental reproduction of Potomac horse fever in horses with a newly isolated Ehrlichia organism

Experimental reproduction of Potomac horse fever in horses with a newly isolated Ehrlichia organism

An Ehrlichia organism was isolated in equine macrophagefibroblast cell cultures and mouse macrophage cell cultures from the mononuclear cells of blood of infected horses.. The agent was [r]

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Molecular cloning of Ehrlichia risticii and development of a gene probe for the diagnosis of Potomac horse fever

Molecular cloning of Ehrlichia risticii and development of a gene probe for the diagnosis of Potomac horse fever

Autoradiogram of the dot blot carrying the DNA from peripheral blood mononuclear cells collected from an experimentally infected horse on different days p.i.. listed to the left.[r]

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The Mari Lwyd and the horse queen : palimpsests of Ancient ideas.

The Mari Lwyd and the horse queen : palimpsests of Ancient ideas.

It has long been suspected (since Crawford 1929) that the horse symbol acted as a totem animal for those that lived in this area. The horse, being on the side of a hill, would be visible from quite a distance away. The archaeological evidence in fact shows that this figure has drifted over time and would have been more visible in ancient times (Green 1992: 154). This supports the idea of a totemic equine sovereignty goddess protecting the fertility of the people. The tribe who cut the Uffington horse is not known. Evidence of later nearby Celtic tribes though is known. The Belgae frequented this area, and a coin of the Dobunni was discovered in Uffington Castle. It should be noted that the Bronze Age date of the Uffington horse more or less corresponds with the earliest archaeological discoveries of equestrian gear. Perhaps supporting this is that some early images of the horse show what appears to be a saddle.
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Potential contaminants at a dredged spoil placement site, Charles City County, Virginia, as revealed by sequential extraction

Potential contaminants at a dredged spoil placement site, Charles City County, Virginia, as revealed by sequential extraction

A former sand and gravel mine site in Charles City County, VA was mined in the 1980s, backfilled with 10 m of sandy mine spoils, and reclaimed to farmland use. The prop- erty owner, i.e., the Weanack Limited Land Partners, bull- dozed the reclaimed mine-spoils into a diked basin and im- ported sediments dredged from the upper Potomac River estuary as fill for the excavated basin in order to convert it to high-quality farmland. However, in theory, the addition of these dredged sediments may influence local groundwater quality. First, the back-filling dredged sediments have the potential of becoming a contaminant source because these dredged estuarine sediments may contain contaminants such as heavy metals that could subsequently enter the groundwa- ter. Second, by adding these dredged sediments into the rec- lamation basin, the in situ conditions could change, poten- tially liberating toxic heavy metals/metalloids to local groundwater. Possible processes that could be induced by the addition of the dredged sediments include: 共1兲 mixing of pore water from the upper Potomac River sediments with the local groundwater, which will affect ionic strength and pH of the dredged sediment pore water and local groundwater; 共2兲 infiltration of the dredged sediments by rain ( pH⬃ 5.6),
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Evaluating a novel sign’s impact on whether park visitors enter a dangerous river

Evaluating a novel sign’s impact on whether park visitors enter a dangerous river

For each captured image (which was our unit of ana- lysis), the reviewer recorded the number of people ob- served on the beach and the number observed in the water. (Note that people who remained in vessels were not counted, since that behavior is legal on the Potomac River.) For each person observed in the water, a study team member documented degree of water entry (i.e., wading, above their knees but below their waist, above their waist but below their shoulders, or above their shoulders). Visitors who were submerged above their shoulders are counted as swimmers, because we could not determine the depth of the water they were in. Also, given the strength of the Potomac River’s current at our study sites, such people were at considerable risk. If a visitor was observed in more than one image, he or she was counted only once. Their sighting was either attrib- uted to the first time they were seen OR to the image in which they performed their most risky behavior (e.g., water entry). Care was taken to distinguish individuals (e.g., visitor apparel was studied, as were hair styles, color of backpacks, etc).
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Characterisation of the horse transcriptome from immunologically active tissues

Characterisation of the horse transcriptome from immunologically active tissues

The horse genome assembly EquCab2 (Wade et al., 2009) was downloaded from Ensembl v71 (www.ensembl.org) and contained 26,991 genes and 29,196 transcripts. CLC Genomics Workbench version 6 (CLC Bio, Aarhus, Denmark, www.clcbio.com) was used to apply quality, SOLiD adapter and Poly-N trimming to the read sequences (File S1). The limit for the removal of low quality sequences was set at 0.2 and a maximum of two ambiguous nucleotides were permitted in each sequence. In CLC each quality score is converted to an error probability where low values represent high quality bases. For each base the error probability is subtracted from the limit (0.2 here). The cumulative total of this value (limit—error) is calculated for each base and it is set at zero if it becomes negative. The retained part of the read will start at the first positive value and end at the highest value of the cumulative total. Any reads less than 20 bp were removed after trimming and the average read lengths were 47 bp. The average coverage values (number of reads x read length/genome size) for each sample based on the aligned reads are shown in Table 1.
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chapter4Greeks

chapter4Greeks

hold hundreds of soldiers, the horse was welcomed as a gift into the city, when the enemy soldiers went to sleep the Greeks climbed out of the wooden horse and slaughtered the enemy.[r]

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Changes In The Horse Racing Industry And Impacts On The Indiana Economy: 2010 - 2014

Changes In The Horse Racing Industry And Impacts On The Indiana Economy: 2010 - 2014

When the 2014 survey was conducted and economic impacts analyzed, it was found that horse racing revenues had dropped significantly to $263 million. However, there was no significant impact on total employment which had been 2,843 full time equivalent jobs in 2009 and was now 2,825 full time equivalent jobs. Similarly, labor income remained steady over that time while the impact on GDP was reduced approximately 25% from $488 million to $366 million. Although there was an insignificant decline in derived federal tax revenues, there was a significant increase in derived state and local taxes. These results are summarized in Table 3.
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A Donkey in a Horse Race

A Donkey in a Horse Race

I didn’t know what made me angrier, the fact that I was like my father or the possibility that I would have children who’d behave just like me.. I started to seriously consi[r]

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Welfare in horse breeding

Welfare in horse breeding

Welfare problems related to the way horses are bred, whether by coitus or by the application of artificial reproduction techniques (ARTs), have been given no discrete consideration within the academic literature. This paper reviews the existing knowledge base about welfare issues in horse breeding and identifies areas in which data is lacking. We suggest that all methods of horse breeding are associated with potential welfare problems, but also that the judicious use of ARTs can sometimes help to address those problems. We discuss how negative welfare effects could be identified and limited and how positive welfare effects associated with breeding might be maximised. Further studies are needed to establish an evidence base about how stressful or painful various breeding procedures are for the animals involved, and what the lifetime welfare implications of ARTs are for future animal generations.
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Colic in the British military working horse population: a retrospective analysis

Colic in the British military working horse population: a retrospective analysis

occurrence of both colic and colic-related deaths within the British military working horse population 355. are similar to those of the general horse population.[r]

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A social and cultural history of the New Zealand horse : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in History, Massey University, Albany, New Zealand

A social and cultural history of the New Zealand horse : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in History, Massey University, Albany, New Zealand

Although a strongly masculine, military culture may have dominated the press and official accounts of the war, there is also evidence that a somewhat softer side of warfare was emerging that revealed itself in the attitude towards the warhorse. As many horses accompanied their owners to the battlefields of South Africa, a relationship would have already existed between horse and soldier stretching back sometimes many years. Those soldiers without horses were assigned a particular animal and it remained their responsibility not only to ride it but also to care for its needs until death or injury separated them. These horses were individualised with names and as soldier and horse were almost in constant company, dependent on each other for their safety and welfare, it is hardly surprising that a close relationship, often referred to as a partnership, existed. Potent reminders of a genuine attachment between horse and rider exist in personal reminiscences and keepsakes. The Kauri Museum at Matakohe contains two such memories. A lock of hair from ‘Charlie’s’ mane on loan from M. Dawson is accompanied by an inscription that tells of Charlie taking his rider safely back to camp after an enemy encounter before falling dead. Another tells of the story of Ben Birt and his remarkable horse, Jagger. The two met at Trentham where Ben, a skilled horseman, was breaking in army remounts. Jagger was a beautiful, spirited, black gelding that had eluded all attempts to tame him. As he had reportedly killed one man and crippled another, he was to be destroyed if Ben was not able to master him. After a ‘mighty battle’, the horse accepted ‘defeat’ and was soon following Ben without bridle or rope. So intelligent was Jagger that he learned commands readily and would come when Ben whistled. Later this would prove a useful trick when man and horse were shipped to South Africa where Ben became a dispatch rider. At times when Ben was riding dispatch and suspicious of ambush, he would leave his horse undercover and scout ahead on foot, having tucked up the reins so that the horse could come if whistled. Jagger would respond to this call at a fast gallop and Ben credited his horse for getting him out of trouble many times. After the war, Jagger was one of the very few horses returned to New Zealand where he lived the rest of his life on the Birt farm as a stockhorse, ‘pet and friend, loyal and reliable until he died’. He is buried on the farm, which had been his home for many years. 57 New Zealand stories such as these echo those told over the ages of the close bond between the warrior and his warhorse.
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The horse in the life and culture of northern nomads

The horse in the life and culture of northern nomads

impulses of the horse breeding process have reached the Arctic territories, where already in the middle Ages, in addition to the crops with appropriating type of farming, there was a cattle-breeding cultural and economic type. This is reflected in the materials of burials of the XVII-XIX centuries, excavated in the Arctic and subarctic regions of Yakutia, where both human burial with a horse and accompanying equipment associated with horse breeding and cult of the horse were found [5]. In the cultural model of cattle breeders-the Sakha, which forms the principles of the organization of the developed space, the marking of its territory is distinguished by the nomination of localities and natural objects (rivers, lakes, mountains). So, economic adaptation to a new landscape of thought and its verbal sanctification by "naming" landmarks of the characters of space: At Haya (Loshad-Gora, Horse Mountain), At Eryus (Loshad-Reka, Horse River), At Kuelyuiea (Loshad- Ozero, Horse Lake), At Yuraeh (Loshad-Ruchey, Horse-Stream), At Balagan (Loshad-Dom, Horse- House). The toponyms associated with the spiritual world of nomad cattle breeders are distinguished, in
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Prevalence of and risk factors for colic in horses that display crib-biting behaviour

Prevalence of and risk factors for colic in horses that display crib-biting behaviour

Owners and carers of horses or ponies that displayed crib-biting/windsucking behaviour were recruited via adverts placed in the equine lay press, online equestrian forums and via the Philip Leverhulme Equine Hospital (University of Liverpool) website. Adverts were also emailed to yards and clubs affiliated with the British Horse Society and were given to local farriers, livery yards, veterinary surgeons and riding instructors. These adverts contained a clear description of crib-biting/ wind- sucking behaviour and no reference was made to any potential relationship between these forms of behaviour and colic. Participants responding to the adverts were asked to complete a postal questionnaire (see
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Implications of Pylodictis olivaris (flathead catfish) introduction into the Delaware and Susquehanna drainages

Implications of Pylodictis olivaris (flathead catfish) introduction into the Delaware and Susquehanna drainages

The mode of flathead catfish introduction into the Delaware and Susquehanna systems remains unknown, but we suggest three scenarios that might account for their presence in these systems: (1) accidental stocking, (2) intentional introduction by anglers, and (3) migration. Firstly, in both basins, Ictalurus punctatus (Rafinesque) (channel catfish) were stocked into reservoirs by the PAFBC to provide sportfishing. These channel catfish fingerlings were provided by public hatcheries that also produced flathead catfish fingerlings, and thus it is possible that flathead catfish fingerlings may have been inadvertently mixed with the channel catfish fingerlings and accidentally stocked into reservoirs adjacent to these rivers (M. Kaufman, pers. comm). Once introduced in reservoirs, fish could easily disperse to the river channel. Secondly, it is possible that the fish were intentionally intro- duced by anglers, who wanted the opportunity to catch a large sport fish close to their residences. Thirdly, flathead catfish may have colonized these two river systems by migration. Flathead catfish may have migrated down- stream from the Potomac River, where they were first introduced in the 1960s, and then moved northward up Chesapeake Bay. From northern Chesapeake Bay, fish may have either entered the Susquehanna River or swam through the Chesapeake and Delaware Canal into the Delaware River. Similarly, flathead catfish from the Delaware Basin may have migrated through the Chesapeake and Delaware Canal into the Chesapeake Bay and into the Susquehanna River.
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