Equine sarcoids are the most common skin tumors of horses. Despite being such a common entity, relatively little is known about many features of sarcoid epidemiology or growth. In addition, due to the detection of Bovine Papillomavirus (BPV) DNA of 2 different types, BPV type 1 (BPV1) and BPV type 2 (BPV2), in equine sarcoids BPV has been suggested as the causative agent of sarcoid development. Recently, however, BPV DNA has also been detected in other skin conditions of horses; the significance of this is unclear. Multiple studies to learn more about sarcoids were undertaken.<p> To investigate the epidemiology of sarcoids in horses in Western Canada the records of five veterinary diagnostic laboratories were searched to identify submissions of sarcoids from horses. The submission record and diagnostic reports of 802 separate submissions of equine sarcoids were reviewed for age, breed, and gender of the horse and the number, location and clinical type of sarcoid. Based on these submissions, horses of a wide variety of ages and 23 different equine breeds were affected, within these breeds, Donkeys were overrepresented.<p> The presence of BPV was determined by Polymerase Chain Reaction (PCR). BPV was found in 74 of 96 (77.1%) samples, and using Restriction Fragment Length Polymorphism, BPV1 and BPV2 were identified in these samples. BPV2 was present in 59 (79.7%) of these. Unlike other areas in the world, in Western Canada, equine sarcoids are most commonly associated with BPV2.<p> A second study examined different clinical types of sarcoids to determine if there was differential expression of immunohistochemical markers associated with apoptosis, Cleaved Caspase 3(ClC3), and antiapoptotic factors, B-Cell Lymphoma 2 (Bcl-2) and Survivin. No differences in the expression of any of these markers regardless of BPV type were noted. Survivin was expressed in equine sarcoids of all types and increased levels of expression are associated with more aggressive clinical behaviour.<p> Finally, the location of BPV DNA was determined in both sarcoids and a variety of non-sarcoid inflammatory skin conditions of horses, as well as, normal skin. PCR for BPV DNA was performed on 86 skin biopsies from horses with non-sarcoid skin conditions, as well as, normal skin. BPV DNA was present in 41 of 86 biopsies. These positive samples, in addition to BPV positive sarcoid samples from the earlier study, were dissected into tissue compartments using laser microdissection followed by 2 forms of BPV DNA amplification, PCR and isothermal loop mediated amplification. BPV DNA was more often located in the epidermis of non-sarcoid skin conditions than in sarcoids. In addition, areas of inflammation within the dermis and epidermis were more likely to contain BPV DNA than non-inflamed areas. These results suggest that while BPV is commonly found in equine skin, the location where it is found differs between sarcoids and non-sarcoid samples. When BPV DNA was found in non-sarcoid samples, it was commonly associated with inflammation suggesting that microscopic damage to the epidermal barrier of the skin maybe an adequate predisposing factor to the development of sarcoids.

This thesis describes the West Nile virus (WNV) epidemic in horses by exploring all aspects: sub-clinical infection, development of clinical disease and case fatality. All of the collected data were then compiled to create predictive risk maps of WNV infection for the province of Saskatchewan. <p>During the 2003 season, 133 clinical cases were documented with laboratory testing. Week of onset of clinical signs, gender, and coat color were significant predictors of whether the horse died or was euthanized due to severity of clinical signs. Studies of the serological response to vaccination and natural infection were examined to interpret the lab results from over 1100 samples taken from approximately 875 horses in 2003. A serologic study involving 212 horses on 20 farms determined the prevalence of sub-clinical infection (55.7% (95%CI, 44.9% to 65.8%)) and identified risk factors for infection. The study found risk of infection was highest in the Grasslands ecoregions compared to the Boreal Transition ecoregion. A case control study looked at risk factors for development of clinical disease. The study followed 23 case farms and control farms with a total of 300 horses sampled. This was the first field study to show that vaccination was efficacious in preventing the development of clinical signs. <p>The inclusion of horse surveillance data in the Saskatchewan Health WNV Integrated Surveillance Initiative was useful; however, it was discontinued due to time constraints, logistics, and declining monetary resources. <p>Since West Nile Virus is a mosquito-borne disease it is highly influenced by environmental changes, spatially and temporally. Discriminant analyses were used to partition Saskatchewan rural municipalities (RM) into categories of risk of infection with WNV based on acquired horse data and different environmental and meteorological data derived from both satellites or climate stations. The result was the creation of yearly predictive risk maps defining low to high risk of infection with WNV for each RM. <p>The 2003 epidemic provided a novel opportunity to study an important zoonotic disease emerging in a new environment. The information gathered will further the knowledge base upon which decisions for prevention of infection and clinical disease are made.

This thesis describes the West Nile virus (WNV) epidemic in horses by exploring all aspects: sub-clinical infection, development of clinical disease and case fatality. All of the collected data were then compiled to create predictive risk maps of WNV infection for the province of Saskatchewan. During the 2003 season, 133 clinical cases were documented with laboratory testing. Week of onset of clinical signs, gender, and coat color were significant predictors of whether the horse died or was euthanized due to severity of clinical signs. Studies of the serological response to vaccination and natural infection were examined to interpret the lab results from over 1100 samples taken from approximately 875 horses in 2003. A serologic study involving 212 horses on 20 farms determined the prevalence of sub-clinical infection (55.7% (95%CI, 44.9% to 65.8%)) and identifed risk factors for infection. The study found risk of infection was highest in the Grasslands ecoregions compared to the Boreal Transition ecoregion. A case control study looked at risk factors for development of clinical disease. The study followed 23 case farms and control farms with a total of 300 horses sampled. This was the first field study to show that vaccination was efficacious in preventing the development of clinical signs. The inclusion of horse surveillance data in the Saskatchewan Health WNV Integrated Surveillance Initiative was useful; however, it was discontinued due to time constraints, logistics, and declining monetary resources. Since West Nile Virus is a mosquito-borne disease it is highly influenced by environmental changes, spatially and temporally. Discriminant analyses were used to partition Saskatchewan rural municipalities (RM) into categories of risk of infection with WNV based on acquired horse data and different environmental and meteorological data derived from both satellites or climate stations. The result was the creation of yearly predictive risk maps defining low to high risk of infection with WNV for each RM. The 2003 epidemic provided a novel opportunity to study an important zoonotic disease emerging in a new environment. The information gathered will further the knowledge base upon which decisions for prevention of infection and clinical disease are made.

This thesis describes the West Nile virus (WNV) epidemic in horses by exploring all aspects: sub-clinical infection, development of clinical disease and case fatality. All of the collected data were then compiled to create predictive risk maps of WNV infection for the province of Saskatchewan. <p>During the 2003 season, 133 clinical cases were documented with laboratory testing. Week of onset of clinical signs, gender, and coat color were significant predictors of whether the horse died or was euthanized due to severity of clinical signs. Studies of the serological response to vaccination and natural infection were examined to interpret the lab results from over 1100 samples taken from approximately 875 horses in 2003. A serologic study involving 212 horses on 20 farms determined the prevalence of sub-clinical infection (55.7% (95%CI, 44.9% to 65.8%)) and identified risk factors for infection. The study found risk of infection was highest in the Grasslands ecoregions compared to the Boreal Transition ecoregion. A case control study looked at risk factors for development of clinical disease. The study followed 23 case farms and control farms with a total of 300 horses sampled. This was the first field study to show that vaccination was efficacious in preventing the development of clinical signs. <p>The inclusion of horse surveillance data in the Saskatchewan Health WNV Integrated Surveillance Initiative was useful; however, it was discontinued due to time constraints, logistics, and declining monetary resources. <p>Since West Nile Virus is a mosquito-borne disease it is highly influenced by environmental changes, spatially and temporally. Discriminant analyses were used to partition Saskatchewan rural municipalities (RM) into categories of risk of infection with WNV based on acquired horse data and different environmental and meteorological data derived from both satellites or climate stations. The result was the creation of yearly predictive risk maps defining low to high risk of infection with WNV for each RM. <p>The 2003 epidemic provided a novel opportunity to study an important zoonotic disease emerging in a new environment. The information gathered will further the knowledge base upon which decisions for prevention of infection and clinical disease are made.

Equine sarcoids are the most common skin tumors of horses. Despite being such a common entity, relatively little is known about many features of sarcoid epidemiology or growth. In addition, due to the detection of Bovine Papillomavirus (BPV) DNA of 2 different types, BPV type 1 (BPV1) and BPV type 2 (BPV2), in equine sarcoids BPV has been suggested as the causative agent of sarcoid development. Recently, however, BPV DNA has also been detected in other skin conditions of horses; the significance of this is unclear. Multiple studies to learn more about sarcoids were undertaken.<p> To investigate the epidemiology of sarcoids in horses in Western Canada the records of five veterinary diagnostic laboratories were searched to identify submissions of sarcoids from horses. The submission record and diagnostic reports of 802 separate submissions of equine sarcoids were reviewed for age, breed, and gender of the horse and the number, location and clinical type of sarcoid. Based on these submissions, horses of a wide variety of ages and 23 different equine breeds were affected, within these breeds, Donkeys were overrepresented.<p> The presence of BPV was determined by Polymerase Chain Reaction (PCR). BPV was found in 74 of 96 (77.1%) samples, and using Restriction Fragment Length Polymorphism, BPV1 and BPV2 were identified in these samples. BPV2 was present in 59 (79.7%) of these. Unlike other areas in the world, in Western Canada, equine sarcoids are most commonly associated with BPV2.<p> A second study examined different clinical types of sarcoids to determine if there was differential expression of immunohistochemical markers associated with apoptosis, Cleaved Caspase 3(ClC3), and antiapoptotic factors, B-Cell Lymphoma 2 (Bcl-2) and Survivin. No differences in the expression of any of these markers regardless of BPV type were noted. Survivin was expressed in equine sarcoids of all types and increased levels of expression are associated with more aggressive clinical behaviour.<p> Finally, the location of BPV DNA was determined in both sarcoids and a variety of non-sarcoid inflammatory skin conditions of horses, as well as, normal skin. PCR for BPV DNA was performed on 86 skin biopsies from horses with non-sarcoid skin conditions, as well as, normal skin. BPV DNA was present in 41 of 86 biopsies. These positive samples, in addition to BPV positive sarcoid samples from the earlier study, were dissected into tissue compartments using laser microdissection followed by 2 forms of BPV DNA amplification, PCR and isothermal loop mediated amplification. BPV DNA was more often located in the epidermis of non-sarcoid skin conditions than in sarcoids. In addition, areas of inflammation within the dermis and epidermis were more likely to contain BPV DNA than non-inflamed areas. These results suggest that while BPV is commonly found in equine skin, the location where it is found differs between sarcoids and non-sarcoid samples. When BPV DNA was found in non-sarcoid samples, it was commonly associated with inflammation suggesting that microscopic damage to the epidermal barrier of the skin maybe an adequate predisposing factor to the development of sarcoids.

This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.

The purpose of this study was: - To investigate jumping sport horses health conditions influence on sport skills; - To investigate blood parameters in Lithuanian jumping sport horses before and after an active training period. Eight healthy horses ranging in age from 6 to 8 with a mean body weight o 607 +/- 86,9 kg were used in experiment. Blood samples were collected from well trained Lithuanian sport horses and tested before and after an intensive period of competition of 2006. Biochemical and morphological blood results were performed to determinate the glucose, triglycerides, cholesterol, red blood cells, haemoglobin, white blood cells, total protein, albumin value, total oxygen consumption and specific oxygen consumption before and after active summer training season. Furthermore, was analyzed mineral substances content of: calcium, potassium, phosphorous, sodium, magnesium and iron in blood serum of jumping sport horses. Physical readiness of horses according changes of haematological parameters before and after active summer competition season were in range of physiological norm. Conclusion: 1. AB ŽŽ/VšĮ “Suvalkijos žirgai” stud farm horses (weight average 544 kg) reached best sport skills in 2006 jumping contest. 2. Fodder supplements during contest season increased sport skills 37, 5%. 3. Red blood cells, haemoglobin, blood oxygen content ware considerable higher in jumping horse’s blood after intensive sport contest season in comparison with pre-contest season. 4... [to full text]

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The purpose of this research was to assess stakeholder interest pertaining to best management practices for free-roaming horses in the Chilcotin, British Columbia. The study site is located between the towns of Hanceville to the east and Tatla Lake to the west. A case study approach was adopted, utilizing on-site observation, document analysis and semi structured interview methods. Analysis, through the reduction and interpretation of data, allowed for the emergence of the themes and subthemes. Themes were free-roaming horse interaction with both the biophysical and socioeconomic landscape as well as management. British Columbia government, ranchers, First Nations and Non Governmental Organizations were interviewed on their awareness and interaction with free-roaming horses, the management and policies pertaining to the species. Free-roaming horses have historically represented a social and economic resource, although stakeholders have had little input into management decisions. Antiquated policies, clashing social values, changing land title and land use and difficult economic times have resulted in a lack of clarity regarding jurisdiction, and therefore management, for the free-roaming horses. Management goals are not clear due to lack of classification as livestock or wildlife under provincial or federal legislations. A strategy, which promotes decentralization, collaboration and transparency in decision and policy-making is recommended. Multi-stakeholder research is the first step toward creating such a strategy.

Sex determination in mammals is regulated by the sex-determining region on the Y chromosome (SRY); the presence of SRY activates the male developmental pathway and suppresses the gene network necessary for female gonad development. Mutations in sex determination genes lead to various abnormal sexual phenotypes, including sex reversal syndrome in which the genetic and phenotypic sex do not match. Sex reversal syndrome has been reported in humans, mouse, and several domestic species. In horses, SRY-negative XY sex reversal syndrome has been well described and is caused by deletions on the Y chromosome. However, the molecular causes of the SRY-positive condition in horses and other mammals are not known. This research investigated five horses affected with SRY-positive XY sex reversal syndrome. Sequencing of the coding exon region of the SRY gene in the five cases showed 99-100% alignment with the sequences of normal males. Genotyping of two closely related individuals with 46 normal male controls on an equine SNP50 Beadchip identified two statistically significant SNPs in a ~16 Mb region on the long arm of horse chromosome 3 (ECA3q). The region was analyzed using Gene Ontology (GO) and Gene Relationships Across Implicated Loci (GRAIL) to select functionally relevant candidate genes for sequencing. Further analysis of the entire horse genome was done through array comparative genomic hybridization (aCGH), which investigated possible structural rearrangements, such as copy number variants (CNVs). Deletions of olfactory receptor genes were detected on multiple chromosomes and confirmed through quantitative real-time PCR (qPCR). A homozygous deletion on ECA29 in a region containing genes of the aldo-keto reductase gene family, known to play a role in interconverting sex hormones between active forms and inactive forms, was discovered in two sex reversed animals. The findings were confirmed through qPCR and fluorescence in situ hybridization (FISH), and experiments to define the specific breakpoints of the deletion through PCR have been initiated. This research represents the first systematic search in the horse genome for mutations and CNVs related to sex determination. The findings contribute to better understanding of the molecular mechanisms of sex determination in horses and other mammals, including humans.