The competence of lymnaeids as intermediate hosts of Fasciola hepatica has not been studied in southern Louisiana and furthermore the taxonomic status of these snails is still controversial among malacologists. There are different opinions as to whether Fossaria (Bakerilymnaea) cubensis or Lymnaea (Pseudosuccinea) columella acts as the main intermediate host in enzootic areas of Louisiana. In the present study, the suitability of those two snails as hosts for F. hepatica from a single source in Louisiana was compared with four other species of lymnaeids from different geographic areas and the study was undertaken with evaluation of 'vector competence'. Groups of young snails were exposed to three different densities of miracidia, 1,5, and 10, in 0.7ml of spring water in a Beem('(REGTM)) capsule during 3 hrs at room temperature. They were checked for infection at day 14 postexposure; then they were dissected or fixed at different times. Percentages, locations of intramolluscan stages and intensity of infection were recorded, as well as the variations in length of the incubation period. Histopathological studies were also done. The results show that L. (P.) columella from Louisiana is a more suitable host (48.6% became infected) than F. (B.) cubensis (19.2% became infected). The percentages of the positive controls becoming infected were: 68.9% for L. (P.) columella from Michigan, and 32.2% for L. gedrosiana from Iran. The study of histological sections did not show any significant differences in the pathological manifestations in the infected snails. The negative controls were: L. natalensis from Senegal, Stagnicola elodes from Michigan, and Stagnicola attenuata from Hidalgo, Mexico, an enzootic area of fascioliasis. The latter species was studied for the first time and its internal anatomy was compared with S. elodes. Although the results show that F. (B.) cubensis and L. (P.) columella have some degree of competence as intermediate hosts of F. hepatica under laboratory conditions, field observations on the habitat of these snails in southern Louisiana and the characteristic management of cattle, indicate that the former snail is more important as an intermediate host in this enzootic area than is the latter / acase@tulane.edu

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3245. Adviser: Robert Knox. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009. / Source: Dissertation Abstracts International, Volume: 70-06, Section: B, page: 3355. Adviser: Wanda M. Haschek-Hock. Includes bibliographical references. Available on microfilm from Pro Quest Information and Learning.

Two experiments were conducted to determine the effects of grain processing, grain sources, protein sources, and bST treatments on lactation performance, ovarian activity and nutrient digestion in early lactation dairy cows. In experiment 1, forty-eight dairy cows were divided into six groups and fed diets containing 37 to 39% grain as either steam-flaked sorghum (SFS, 360 g/L), steam-flaked corn (SFC, 360 g/L), or steam-rolled corn (SRC, 490 g/L) with one of two protein sources, soybean meal (SBM) or Prolak® for 70 days. Main effects for grain and protein source were not different for DMI, milk yield, 3.5% FCM yield or feed efficiency. Although efficiency of feed conversion into FCM did not differ among treatments, cows fed Prolak® required 10% less NEL for every Mcal of NEL converted into body weight or FCM. Milk protein yield was increased by both flaked gain and Prolak®. Feeding flaked grain increased milk production by 1.5 kg/d compared with rolled grain. Increasing the ratio of RDS/RDP to more than 2.4 increased milk yield by 2.7 kg/d (39.0 vs 36.3 kg/d). Plasma NEFA levels did not differ among treatments and grain and protein source had variable effects on PUN. Compared with other grains, SFC increased digestibilities of DM and OM, and flaked grains increased digestibility of starch. Cows fed SFS had the lowest crude protein digestibility, but was highest in NDF. In experiment 2, thirty-two postpartum (5 DIM)Holstein cows were assigned to one of four treatments in a 2 x 2 factorial design for 90 days. Treatments were: steam-flaked sorghum diet with bST (SFS-B); steam-flaked sorghum diet without bST (SFS-N); steam-rolled corn diet with bST (SRC-B); and steam-rolled corn diet without bST (SRC-N). Cows receiving bST during the first 45 days of treatment had lower DMI and DMI as % of BW. Milk yield was increased by bST 3.1 kg/d and 1.8 kg/d during the 45 d and 90 d periods, respectively, resulting in greater feed efficiency for bST-treated cows. Grain processing did not affect DMI, milk yield and FCM yield. Neither composition nor yields of milk components were influenced by treatments. Compared to the SRC diet, SFS increased plasma glucose 5% and plasma insulin 19%. Grain processing and bST had no effect on either BHBA or hepatic triglycerides. PUN was reduced by bST, but NEFA was increased. Compared with SRC, SFS increased progesterone during the first two postpartum estrous cycles and cows receiving bST had significantly larger CL. Flaked sorghum compared with SRC increased digestibility of DM, OM, and starch, and neither grain affected digestibilities of CP, NDF or ADF. Treatments with bST did not affect any nutrient digestibilities.

Insect and rodent samples were collected from suspected VSV-NJ enzootic areas over 2 consecutive field seasons (1996-1997) and from southern Arizona only during 1998. Insect samples were screened for arboviruses, and rodent sera were tested for the presence of VSV-NJ and VSV-IN neutralizing antibodies. Vesicular stomatitis virus New Jersey serotype was isolated from a pool of Culicoides sp. collected in 1997 near Belen, New Mexico. All rodent sera were negative for specific VSV-NJ and VSV-IN antibodies. Genetic analysis of the hypervariable region of the phosphoprotein gene demonstrated that the 1997 Belen VSV-NJ isolate was more closely related to viruses isolated from livestock during the 1982-83 western U.S. epizootic than to other VSV-NJ isolates. This suggests that VSV-NJ may be enzootic in the western U.S. Simulium vittatum was shown to be a competent vector of VSV-NJ. Virus-infected females were allowed to feed on laboratory mice and on deer mice. All laboratory mice seroconverted by day 21 post-exposure. Neutralizing antibody titers increased from an average of 1:4 at baseline to >1:1,024 on day 21. An age-related effect on viral pathogenesis was evident in Peromyscus maniculatus following VSV-NJ exposure by black fly bite. Lethal encephalomyelitis was evident in all 6-week-old mice, but in only one 6-month-old mouse. Peromyscus maniculatus did not meet the standard definition of a reservoir host for VSV-NJ because a viremia, was not detected. Nonetheless, P. maniculatus may play a role in virus maintenance since non-infected black flies became infected while co-feeding with infected black flies on the same non-viremic host. These results represent the first example of a western U.S. insect species becoming infected with VSV-NJ by feeding on a host. Simulium vinatum and S. notatum were shown to be competent laboratory vectors of VSV-IN. Saliva from experimentally infected Simulium vittatum and S. notatum was collected and tested for the presence of infectious virus. Virus was detected in the saliva of both species following oral infection. Independent experiments were conducted to determine if transovarial transmission of VSV-NJ and VSV-IN occurs in black flies. Transovarial transmission was not detected. Transstadial transmission of both virus serotypes was detected.

<p> Feline oral squamous cell carcinoma (SCC) is a devastating disease that responds poorly to traditional treatment modalities. The tumor location directly impacts the patient's ability to eat and drink, and immediate intervention to alleviate clinical signs is important. To design better treatment strategies it is paramount to understand the underlying biological behavior of this poorly defined tumor. This research takes a comprehensive approach in attempt to understand this disease. A number of assays have been developed and applied to elucidate underlying biology. New imaging modalities have been used to better stage the disease and define tumor location. Finally, patients were treated with a new radiation therapy modality, stereotactic radiation therapy (SRT), and outcome was correlated with the biological assays for potential predictive value. </p><p> The goal of the prospective study described in Chapter 2 was to compare gross tumor volume measurements using ¹⁸F-FDG PET vs. those using computed tomography (CT) for SRT planning in cats with oral SCC. Twelve cats with confirmed oral SCC underwent pretreatment ¹⁸F-FDG PET/CT. Gross tumor volumes based on contrast-enhanced CT and ¹⁸F-FDG PET were measured and compared between cats. Mean PET gross tumor volume was significantly smaller than mean CT gross tumor volume in the mandibular/maxillary SCC group (n=8, <i>P</i>=0.002) and for all cats (n=12, <i> P</i>=0.006), but not for cats with lingual/laryngeal SCC (n=4, <i> P</i>=0.57). Mismatch fraction analysis revealed that most of the lingual/laryngeal patients had a large region of high-¹⁸F-FDG activity outside of the CT gross tumor volume. This mismatch fraction was significantly greater in the lingual/laryngeal group than the mandibular/maxillary group (<i> P</i>=0.028). The effect of poor spatial resolution of PET imaging was greater when the absolute tumor volume was small. Findings from this study indicated that ¹⁸F-FDG PET warrants further investigation as a supplemental imaging modality in cats with oral SCC because it detected presumed regions of primary tumor that were not detected on CT images.</p><p> For canine and feline patients with tumors in the head region, simultaneous irradiation of the primary tumor and mandibular and retropharyngeal lymph nodes (LNs) is often indicated. The purpose of this study described in Chapter 3 was to assess the reliability of a planning target volume (PTV) expansion protocol for secondary targets (LNs). </p><p> Information about the molecular biology of feline oral SCC is still limited. In Chapter 4, 22 archived tumor samples of feline oral SCC were evaluated to develop immunohistochemical assays and to determine if there was correlation to clinical parameters. Immunohistochemistry for Ki67, MVD, and EGFR was performed and scored. Patient survival information was obtained from the medical records. These molecular markers as well as MI were correlated with tumor locations and patient survival time. The 22 tumors showed wide variation in Ki67, MI, MVD, and EGFR. Tongue SCC expressed higher MVD than mandibular/maxillary SCC (<i>P</i>=0.088). </p><p> Cancer stem cell or tumor initiating cell (TIC) theory and telomere biology are actively studied fields in human head and neck (H&amp;N) cancer. In feline oral SCC, which has been advocated as a feline model for human H&amp;N cancer, our knowledge about the TIC and telomere/telomerase biology is limited. Protein expression levels of putative TIC markers of human H&amp;N cancer, CD44 and Bmi-1, were immunohistochemically evaluated for their possible role as prognostic markers in 20 patients with feline oral SCC who underwent SRT. This patient population was part of a clinical trial and information relevant to PFI and ST was available. A combined technique of fluorescent in-situ hybridization and immunofluorescent staining was used to determine telomere length ratio (fractions of very short telomere/average length telomere in the putative cancer stem cells) in the putative TICs that were positive for CD44 and Bmi-1. This was also correlated with treatment outcome. (Abstract shortened by UMI.) </p>

Thesis (Ph.D.)--University of California, Davis, 2006. / (UMI)AAI3236039. Adviser: Roberto Sainz. Source: Dissertation Abstracts International, Volume: 67-09, Section: B, page: 4768.

<p> This thesis considers the prospects for including respect for patient autonomy as a value in veterinary medical ethics. Chapter One considers why philosophers have traditionally denied autonomy to animals and why this is problematic; I also present contemporary accounts of animal ethics that recognize animals&rsquo; capacity for and exercise of autonomy (or something similar, such as agency) as morally important. In Chapter Two, I review veterinary medical ethics today, finding that respect for patient autonomy is undiscussed or rejected outright as irrelevant. Extrapolating mainstream medical ethics&rsquo; account of autonomy to veterinary medicine upholds this conclusion, as it would count all patients as &ldquo;never-competent&rdquo; and consider determining their autonomous choices impossible; thus welfare alone would be relevant. Chapter Three begins, in Part I, by describing the ways we routinely override patient autonomy in veterinary practice, both in terms of <i>which</i> interventions are selected and <i>how</i> care is delivered. I also show that some trends in the field suggest a nascent, implicit respect for patient autonomy. Part II of Chapter Three presents feminist criticisms of the mainstream approach to patient autonomy. I argue that the relational approach to autonomy advocated by such critics can be meaningfully applied in the veterinary realm. I advance an approach that conceives respect for patient autonomy in diachronic and dialogic terms, taking the patient as the foremost locus of respect. In Chapter Four, I turn to issues of practical implementation, such as interpreting what constitutes an animal&rsquo;s values and concerns, and assessing the effect of positive reinforcement training on autonomy. The Conclusion offers areas for future research while refuting the objection that a simpler, expanded welfare-based approach would yield the same substantive recommendations as my account.</p><p>

There is a dearth of information pertaining to the occurrence and prevalence of filarial helminth infections of dogs and cats in several provinces in South Africa. In this context the dissertation is a pilot survey that was conducted to determine the occurrence and prevalence of filarial helminth infections of dogs in the greater Mahikeng Local Municipality of North West province. The incentive for the choice of this location in the North West province was a reported high overall prevalence of 18 % of canine filariosis in the town of Gaborone in neighbouring Botswana. EDTA blood samples were collected from 100 live dogs between the ages of 1-11 years (53 males and 47 females). Only dogs that had not received treatment with macrocyclic lactone actives during the previous 12 months were included in the survey. A total of 13 different dog breeds were involved in the survey and the crossbreed animals were the most abundant (59 %) followed by the Boerboel (9 %). Blood samples were screened for the presence of microfilariae by means of the membrane filtration technique. There was no evidence of filarial infections in the 100 dogs sampled. / Dissertation (MSc)--University of Pretoria, 2018. / Veterinary Tropical Diseases / MSc / Unrestricted

Rhipicephalus microplus transmit two important diseases of livestock in South Africa, namely Babesiosis and Anaplasmosis. As cattle still play a key role in the livelihood of rural communities in the Eastern Cape province, animal health is of utmost importance to maintain and strengthen these communities. In most rural areas of the Eastern Cape, the South African government provides free dipping of cattle with amitraz. Deltamethrin, a synthetic pyrethroid (SP), has been used as pour-on dip in a few locations where there are no functional dips. Of concern, is the growing number of global reports on the increase of acaricide resistance. Routine screening for resistance to acaricides is therefore needed. In this study we investigated allele frequencies of acaricide resistance-associated single nucleotide polymorphisms (SNPs) in R. microplus ticks from the Engcobo Local Municipality. The estimated frequencies of amitraz resistance-associated SNPs were 0.58 (at locus 1) and 0.32 (at locus 3). Resistance against formamidines (amitraz) appears to be on the rise. The published mutation in the voltage gated sodium channel (VGS) receptor gene (domain II segment 4-5 region), known to confer resistance to synthetic pyrethroids, was not found. This could be attributed to the low selection pressure against pyrethroids in the study area. / Dissertation (MSc)--University of Pretoria, 2018. / Veterinary Tropical Diseases / MSc / Unrestricted