No description available.

Thesis (Ph. D.)--Michigan State University. Dept. of Animal Science, 2006. / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 127-153). Also issued in print.

Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: Eugene G. Mueller, Dept. of Chemistry & Biochemistry. Includes bibliographical references.

Doctor of Philosophy / Department of Anatomy and Physiology / Johann F. Coetzee / Flunixin meglumine has been used as an antipyretic and anti-inflammatory since the 1980s. In 2013, a novel formulation was released in the European Union for topical administration and transdermal absorption. Approval for transdermal flunixin in cattle in the United States occurred in 2017, and included a label claim for the control of pain associated with infectious pododermatitis (foot rot). This new formulation allows for needle-less delivery of flunixin with minimal restraint and training required. In this dissertation, the pharmacokinetics of transdermal flunixin in Holstein calves at 2 months of age and adult lactating cows is described. In these pharmacokinetic studies, plasma flunixin concentrations were determined using high-pressure liquid chromatography coupled with mass spectroscopy. Pharmacokinetic modeling was completed using non-compartmental modeling methods using a commercially available computer program. Ex vivo prostaglandin E₂ (PGE₂) production using a whole blood model served as a biomarker for the anti-inflammatory effects of flunixin meglumine and suppression of cyclo-oxygenase enzyme-2. The concentrations of PGE₂ were determined using a commercially available enzyme-linked immunosorbent linked assay (ELISA) kit. The effects of age and pain on the pharmacokinetics of flunixin were investigated. Both influenced the pharmacokinetics and anti-inflammatory effects of flunixin. Cautery dehorning without local anesthetic was used in the calf model to generate pain. The pain associated with dehorning caused lower absorption of the transdermal flunixin and a longer terminal half-life. This longer half-life did result in lower PGE₂ concentrations at later time points. The influence of age was determined in the same group of Holstein calves at 2 months and 8 month of age. Age related effects included lower clearance, a longer half-life, and longer suppression of PGE₂ following intravenous injection. Following transdermal administration, older animals had a prolonged absorption leading to a longer half-life and apparent ‘flip-flop’ pharmacokinetics. Additionally, the suppression of PGE₂ was not observed in older calves following transdermal flunixin administration. The analgesic properties of transdermal flunixin were tested using three different pain models. Those pain models include cautery dehorning, surgical castration, and induced lameness. The reduction in plasma cortisol following transdermal administration was the most consistent finding in each model for pain. Infrared thermography (IRT) was used to assess either activation of the autonomic nervous system or local inflammation. Flunixin did not have any effects on substance P concentration in all three pain models. Gait analysis using a floor based pressure mat was used in the assessment of castration and lameness pain. Although there were no observed effects of flunixin in those studies, the use of this technology for pain assessment is promising. Future studies of transdermal flunixin to determine its utility as part of a multi-modal analgesic plan are still warranted. Specifically, the use a of a local anesthetic block at the time of cautery dehorning, as flunixin has minimal effects on pain, and its pharmacokinetics were altered by the painful stimulus. Timing of the dose relative to the painful procedure is also needed as flunixin is rapidly absorbed. Field studies in lame cattle are needed as there is a deficiency in the literature as only models of lameness induction have been reported.

No description available.

No description available.

Health intervention schemes have previously been used in order to improve animal welfare and to reduce and sometimes eradicate disease (Bell et al., 2009). This investigation looks at the success of one such scheme upon the incidence of cattle lameness. Farmers participating in the Healthy Livestock Scheme, which took place in the South West of England from November 2010- January 2014, had their cattle mobility scored before commencing any mentored training, to determine pre-intervention lameness prevalence and again after intervention. The results confirm there was a significant reduction in lameness, from an average 26.7% lame before any intervention to 20.4% after. This means there was on average, 23.6% fewer cases of lameness after farms had participated in the Healthy Livestock Scheme, than before. In an average 128 cow herd, this equates to seven fewer cows becoming lame each year and, based on a single case of lameness costing £180 (AHDB, 2016), this represents a significant saving of £1,283 per annum. Importantly, none of the independent variables had a significant effect upon the change in lameness seen between pre and post-intervention mobility scores. This means the Healthy Livestock scheme was effective at reducing lameness regardless of farming system, breed, herd size, housing, or number of FTEs. The wider implications of this mean that, crucially, this type of funded vet and farmer interaction reaps benefits for all farm types, regardless of these factors.

Call number: LD2668 .T4 1979 E37 / Master of Science

Call number: LD2668 .T4 1979 G45 / Master of Science

Lameness is the most common medical complaint amongst domestic horses. Consequently, lameness assessment skills are expected of veterinary graduates as a day one skill by the Royal College of Veterinary Surgeons. However, recognising lameness is inherently difficult, especially for mild cases: even experienced assessors regularly disagree on the affected limb. The impact of a resulting misdiagnosis can be profound for both horse and owner. Even today, the biomechanical changes associated with lameness and the mechanisms of subjective clinical decision making are far from understood. Not surprisingly, there is currently no standardised way to teach students the 'art' of lameness detection. Hence, this thesis investigated core elements of the lameness examination in the framework of task analysis, combining biomechanics, vision science and educational research. Mechanical principles of movement asymmetry adaptations associated with locomotion of sound and lame horses on the straight, circle and after flexion tests were investigated. Subjective perception and objective quantification of asymmetry were compared, ranging from detection thresholds of naIve observers to factors influencing experienced veterinarians. Student performance at different stages was evaluated to understand the foundations students bring to future training. Expert visual approaches to lameness detection were quantified by means of eyetracking, investigating whether general principles can be derived to guide teaching. This work showed that it is possible to model and consequently simplify movement adaptations during lameness for future computer based training tools, however a systematic asymmetry bias of sound horses during lunging and after limb flexion needs to be considered. Differences between visual perception and objective quantification of asymmetry highlight the need for further exploration of perception-based diagnostics. While experts used relatively similar approaches when examining horses on the straight, there were considerable differences during assessment on the circle; in future, it would be of benefit to. develop a reliable and uniform assessment strategy.