PubMed | University of Chester and Westpoint Veterinary Group
Type: | Journal: Preventive veterinary medicine | Year: 2016
This study used probabilistic elicitation and a Bayesian framework to quantitatively explore how logically practitioners update their clinical beliefs after exposure to new data. The clinical context was the efficacy of antibiotics versus teat sealants for preventing mammary infections during the dry period. While most practitioners updated their clinical expectations logically, the majority failed to draw sufficient strength from the new data so that their clinical confidence afterwards was lower than merited. This study provides quantitative insight into how practitioners update their beliefs. We discuss some of the psychological issues that may be faced by practitioners when interpreting new data. The results have important implications for evidence-based practice and clinical research in terms of the impact that new data may bring to the clinical community.
PubMed | Westpoint Veterinary Group, University of Liverpool and University of Surrey
Type: | Journal: Journal of dairy science | Year: 2017
In the United Kingdom, blanket antibiotic dry cow therapy (BDCT) is commonly prescribed. An alternate strategy is selective dry cow therapy (SDCT) whereby a teat sealant is given instead of an antibiotic to cows with a low probability of infection. Switching from BDCT to SDCT can significantly reduce antibiotic use. The aims of this study were to explore how veterinarians (vets) rationalized their prescribing decisions for mammary treatments at drying off, and the barriers and motivators they perceived to implementing SDCT. Face-to-face interviews were conducted with 20 purposively recruited vets from 6 practices in England, United Kingdom. The data were analyzed qualitatively using an inductive thematic analysis. The majority of participants stated a personal preference for SDCT because it constitutes more responsible antibiotic use. On the majority of farms, the prescribing decision was taken by a senior veterinarian and BDCT was prescribed. Less experienced vets expressed a desire to be more involved in the decision-making process. The first theme, prioritizing responsible antimicrobial prescribing, encapsulated the difficulties vets expressed engaging with farmers, conflicts of interest, and vets determination to take action. The second theme, the effect of a vets experience on their ability to influence farmers, focused on the specific challenges faced by less experienced vets and the importance of vets being both trusted by farmers and being knowledgeable. The third theme, vets perceptions about the risk and complexity of implementing SDCT, revealed markedly different levels of concern and fears about adverse outcomes with teat sealants versus antibiotics. The results also showed differences in perceptions about how difficult SDCT is to implement in practice. The last theme, vets suggestions for facilitating the introduction of SDCT, was wide ranging and provided useful insight from a veterinary perspective into ways to facilitate SDCT. Initiatives that seek to alter vets perceptions of the risks associated with switching to using SDCT are likely to prove useful in facilitating change. Our results also suggest that it is vital for senior vets to take a leading role in facilitating farms to implement SDCT. Less experienced colleagues may benefit from more help from senior vets to gain the trust of farmers and to become involved more quickly in herd-level preventive medicine. Vets must work together and take a united approach to reduce antimicrobial use.
Bartram D.J.,Fort Dodge Animal Health |
Heasman L.,Westpoint Veterinary Group |
Batten C.A.,Institute for Animal Health |
Oura C.A.L.,Institute for Animal Health |
And 3 more authors.
Veterinary Journal | Year: 2011
Cattle and sheep that had received a primary course of vaccination with an inactivated bluetongue virus serotype 8 (BTV-8) vaccine were booster vaccinated 6 or 12. months later with the homologous vaccine or an alternative inactivated BTV-8 vaccine and neutralising antibody responses were determined. Antibody titres to the alternative vaccine were significantly higher than to the homologous vaccine (P= 0.013) in cattle. There was no significant difference between the antibody responses to alternative and homologous vaccines in sheep. These data indicate that cattle and sheep primed with one inactivated BTV-8 vaccine may be effectively boosted with an alternative commercial inactivated BTV-8 vaccine. © 2010 Elsevier Ltd.
Sidhu P.,The Royal Veterinary College |
Sidhu P.,Guru Angad Dev Veterinary and Animal Sciences University |
Rassouli A.,The Royal Veterinary College |
Rassouli A.,University of Tehran |
And 7 more authors.
Journal of Veterinary Pharmacology and Therapeutics | Year: 2014
Florfenicol was administered subcutaneously to 10 calves at a dose of 40 mg/kg. Pharmacokinetic-pharmacodynamic (PK-PD) integration and modelling of the data were undertaken using a tissue cage model, which allowed comparison of microbial growth inhibition profiles in three fluids, serum, exudate and transudate. Terminal half-lives were relatively long, so that florfenicol concentrations were well maintained in all three fluids. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration were determined in vitro for six strains each of the calf pneumonia pathogens, Mannhemia haemolytica and Pasteurella multocida. An PK-PD integration for three serum indices provided mean values for P. multocida and M. haemolytica, respectively, of 12.6 and 10.4 for Cmax/MIC, 183 and 152 h for AUC0-24 h/MIC and 78 and 76 h for T>MIC. Average florfenicol concentrations in serum exceeded 4 × MIC and 1.5 × MIC for the periods 0-24 and 48-72 h, respectively. Ex vivo growth inhibition curves for M. haemolytica and P. multocida demonstrated a rapid (with 8 h of exposure) and marked (6 log10 reduction in bacterial count or greater) killing response, suggesting a concentration-dependent killing action. During 24-h incubation periods, inhibition of growth to a bacteriostatic level or greater was maintained in serum samples collected up to 96 h and in transudate and exudate samples harvested up to 120 h. Based on the sigmoidal Emax relationship, PK-PD modelling of the ex vivo time-kill data provided AUC0-24 h/MIC serum values for three levels of growth inhibition, bacteriostatic, bactericidal and 4 log10 decrease in bacterial count; mean values were, respectively, 8.2, 26.6 and 39.0 h for M. haemolytica and 7.6, 18.1 and 25.0 h for P. multocida. Similar values were obtained for transudate and exudate. Based on pharmacokinetic and PK-PD modelled data obtained in this study and scientific literature values for MIC distributions, Monte Carlo simulations over 100 000 trials were undertaken to predict once daily dosages of florfenicol required to provide 50% and 90% target attainment rates for three levels of growth inhibition, namely, bacteriostasis, bactericidal action and 4 log10 reduction in bacterial count. © 2013 John Wiley & Sons Ltd.
Guido S.,Moredun Research Institute |
Guido S.,University of Edinburgh |
Katzer F.,Moredun Research Institute |
Nanjiani I.,Westpoint Veterinary Group |
And 2 more authors.
Trends in Parasitology | Year: 2016
The protozoan Neospora caninum is a primary infectious cause of abortion in cattle that causes significant economic losses worldwide. Because effective vaccines and licensed pharmacological treatments are currently unavailable, control measures rely on biosecurity and management practice. Serological diagnosis plays a crucial role in the identification of infected animals and several tests have been developed. However, owing to the particular dynamics of the host-parasite interaction and to the characteristics of the currently used diagnostic tools, a proportion of infected cattle may not be reliably identified, and can potentially undermine efforts towards the control of bovine neosporosis. Current diagnostic methods for N. caninum infection in cattle and the advances necessary to support effective control strategies are discussed. © 2015 Elsevier Ltd.
PubMed | Moredun Research Institute, Westpoint Veterinary Group, Roslin Institute and University of Edinburgh
Type: Journal Article | Journal: Trends in parasitology | Year: 2016
The protozoan Neospora caninum is a primary infectious cause of abortion in cattle that causes significant economic losses worldwide. Because effective vaccines and licensed pharmacological treatments are currently unavailable, control measures rely on biosecurity and management practice. Serological diagnosis plays a crucial role in the identification of infected animals and several tests have been developed. However, owing to the particular dynamics of the host-parasite interaction and to the characteristics of the currently used diagnostic tools, a proportion of infected cattle may not be reliably identified, and can potentially undermine efforts towards the control of bovine neosporosis. Current diagnostic methods for N. caninum infection in cattle and the advances necessary to support effective control strategies are discussed.
Potter T.,Royal Veterinary College |
Potter T.,Westpoint Veterinary Group |
Illambas J.,Royal Veterinary College |
Illambas J.,European Service Center |
And 3 more authors.
Veterinary Journal | Year: 2013
The pharmacokinetics (PK) and pharmacodynamics (PD) of marbofloxacin were established in calves for six strains of each of the pneumonia pathogens Mannheimia haemolytica and Pasteurella multocida. The distribution of marbofloxacin into inflamed (exudate) and non-inflamed (transudate) tissue cage fluids allowed comparison with the serum concentration-time profile. To establish the PD profile, minimum inhibitory concentration (MIC) was determined in Mueller-Hinton broth (MHB) and calf serum.Moderately higher MICs were obtained for serum compared to MHB. An initial integration of PK-PD data established Cmax/MIC ratios of 45.0 and AUC24h/MIC values of 174.7h, based on serum MICs, for both bacterial species. Using bacterial time-kill curves, generated ex vivo for serum marbofloxacin concentrations, PK-PD modelling established three levels of growth inhibition: AUC24h/MIC ratios for no reduction, 3 log10 and 4 log10 reductions in bacterial count from the initial inoculum count were 41.9, 59.5 and 68.0h for M. haemolytica and 48.6, 64.9 and 74.8h for P. multocida, on average respectively. Inter-strain variability for 3 log10 and 4 log10 reductions in bacterial count was smaller for P. multocida than for M. haemolytica. In conjunction with literature data on MIC90 values, the present results allowed prediction of dosages for efficacy for each organism for the three levels of growth inhibition. © 2012 Elsevier Ltd.
Lees P.,Royal Veterinary College University of London |
Potter T.,Westpoint Veterinary Group
Journal of the Royal Agricultural Society of England | Year: 2011
The use of antimicrobial drugs (AMDs) in farm animal medicine is both necessary and justified on welfare and economic grounds. However, antimicrobial resistance in microorganisms colonising farm animal species is a growing problem, despite encouragement to use these drugs in a prudent manner. At this time, evidence of the link between the use of medicines in farm animals and the emergence of resistance in human microorganisms remains limited. Nevertheless, we must continue to strive to achieve rational use and optimisation of dosage regimens of AMDs to maintain their effectiveness and thereby ensure animal welfare.
Potter T.J.,Westpoint Veterinary Group
Cattle Practice | Year: 2011
The wide use of antimicrobial drugs in the control of cattle diseases has led to concerns over the potential for emergence of resistance and the associated risks to human health. In response to these concerns and to maintain the efficacy of the available products it is important that veterinary surgeons develop an evidence based approach to their use of antimicrobials in conditions such as calf pneumonia, taking into account knowledge of a drug's pharmacokinetics and pharmacodynamics.
Potter T.,Westpoint Veterinary Group
Cattle Practice | Year: 2012
Antimicrobials have made a major contribution to cattle health and welfare and they are vital medicines for the treatment of bacterial infections in cattle and other livestock. The emergence of antimicrobial resistance as a serious problem in human medicine has prompted concerns about the potential for crossover of resistant bacteria from livestock to the human population and the associated possibility of this impacting on the effectiveness of medical antimicrobial treatments. The European Centre for Disease Prevention and Control (ECDC) estimates that antimicrobial resistance results each year in 25,000 deaths and related costs of over €1.5 billion in healthcare expenses and productivity losses. The appearance in human pathogens of resistance to multiple antimicrobials has focused attention on both human and veterinary use of these valuable medicines. However, the degree to which usage of antibiotics in veterinary medicine contributes to this problem is yet to be fully understood. The development of resistance can be minimised provided that a number of measures are implemented. This presentation will discuss some of the policies that can be instigated at a practice level to ensure the responsible usage of antimicrobials.