Publications by authors named "Andy E Durham"

13 Publications

  • Page 1 of 1

Clinically and temporally specific diagnostic thresholds for plasma ACTH in the horse.

Equine Vet J 2021 Mar 23;53(2):250-260. Epub 2020 Jun 23.

Mathematics and Statistics, ITMAS, College of Science, Health, Engineering and Education, Murdoch University, Western Australia, Australia.

Background: Pituitary pars intermedia dysfunction (PPID) is commonly investigated using plasma ACTH concentrations but problems exist with currently available diagnostic thresholds.

Objectives: To derive temporally specific diagnostic thresholds for equine plasma ACTH concentration to be used alongside clinical judgement in each individual week of the year and appropriate for the degree of clinical suspicion in any given case. Furthermore, to apply these thresholds to compare the prevalence of high and low ACTH in two subgroups of animals with high and low clinical suspicion of PPID.

Study Design: A retrospective population study examining a large laboratory database of equine plasma ACTH concentrations using an indirect approach to calculate diagnostic thresholds.

Methods: Logs of plasma ACTH concentrations from 75 892 individual horses were examined using robust L estimation of mixtures of two normal distributions in categories of each week and month of the year. Thresholds dividing the two populations of high-ACTH and low-ACTH horses were then established at different levels of sensitivity and specificity and compared with clinical subgroups of horses divided based on reported clinical signs, as having high (n = 4036) or low (n = 3022) clinical suspicion of PPID.

Results: For most of the year there were small interweek differences in diagnostic thresholds. However, from mid-June to early-December diagnostic thresholds showed greater interweek variability, reaching a maximum in late September and early October. Grouping of high- and low-ACTH compared favourably with grouping based on clinical signs.

Main Limitations: Given the multiple sources of diagnostic samples, pre-analytical data could not be fully verified.

Conclusions: Diagnostic thresholds for equine plasma ACTH vary through the year. It is especially important to consider the temporally specific threshold between June and December. Different clinical thresholds can be used depending on the case circumstances and whether a false-positive or false-negative diagnosis is deemed least desirable.
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http://dx.doi.org/10.1111/evj.13292DOI Listing
March 2021

Failure of serological testing for antigens A and C of Streptococcus equi subspecies equi to identify guttural pouch carriers.

Equine Vet J 2021 Jan 20;53(1):38-43. Epub 2020 May 20.

Bransby Horses, Bransby, Lincoln, UK.

Background: Serology is commonly used as a means of identifying horses that might be chronic and silent carriers of S. equi but its sensitivity is rarely examined.

Objectives: The study was designed to investigate the sensitivity of serological testing for antibodies against S. equi antigens A and C to detect guttural pouch carriers of S. equi.

Study Design: Retrospective clinical study.

Methods: As part of routine surveillance and quarantine procedures horses arriving at a welfare charity quarantine unit were subject to both microbiological sampling of guttural pouches and also serological testing for antibodies directed at S. equi antigens A and C. Laboratory results and endoscopic findings were examined to determine associations between serological results and guttural pouch carriage of S. equi.

Results: Of 287 included horses, 9 (3.1%) were found to be guttural pouch carriers. There was no significant association between serological status and guttural pouch carriage of S. equi Only one of the nine carriers (11%) was seropositive using a cut-off of OD ≥ 0.5, and only three of nine (33%) using a cut-off of OD ≥ 0.3.

Main Limitations: Horses examined in this study were new arrivals at a welfare centre rather than from a general, well-managed, equid population. As a retrospective clinical study, the laboratory test results could not be repeated for further confirmation.

Conclusions: Caution is advised when relying on seronegativity to antigens A and C in order to discount the possibility of chronic carriage of S. equi in guttural pouches.
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http://dx.doi.org/10.1111/evj.13276DOI Listing
January 2021

Antimicrobial susceptibility of bacterial isolates from ambulatory practice and from a referral hospital.

J Vet Intern Med 2020 Jan 17;34(1):300-306. Epub 2019 Dec 17.

The Liphook Equine Hospital, Hampshire, United Kingdom.

Background: Responsible use of antimicrobials in equine practice relies on knowledge of common bacterial isolates and their antimicrobial sensitivities.

Objectives: To assess the frequency of bacterial resistance to a combination of parenteral penicillin and gentamicin and to trimethoprim and sulfamethoxazole for PO use in a selection of clinical isolates, and subsequently to determine the prevalence of resistance to antimicrobials that might then be used as alternatives to first-line antimicrobials for the same isolates.

Methods: Retrospective analysis of minimal inhibitory concentrations (MICs) of antimicrobials for 6354 bacterial isolates from 365 ambulatory practices and 519 isolates from a referral hospital. The MICs were used to indicate sensitivity or resistance to commonly used antimicrobials and the prevalences of resistance were compared between origin of the isolates, and among antimicrobial drugs.

Results: Isolates from the referral hospital were significantly (P < .05) more likely to be resistant to the antimicrobials tested than those derived from ambulatory practice. Overall, 91% of the ambulatory isolates and 64% of the hospital isolates were sensitive to penicillin-gentamicin. For trimethoprim-sulfamethoxazole combination, 82% of the ambulatory practice isolates and 56% of the referral hospital isolates were sensitive.

Conclusions And Clinical Importance: Most isolates were sensitive to penicillin and gentamicin as well as trimethoprim-sulfamethoxazole. No predictable efficacious second choice antimicrobial was identified for those isolates resistant to the first-line antimicrobials. The likelihood of isolates being sensitive to second choice antimicrobials was variable but generally higher for ambulatory isolates compared to referral isolates. Bacterial identification and measurement of MIC are essential to make the appropriate antimicrobial choice.
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http://dx.doi.org/10.1111/jvim.15685DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6979268PMC
January 2020

Response to letter to editor regarding ECEIM consensus statement on equine metabolic syndrome.

J Vet Intern Med 2019 05 16;33(3):1125-1126. Epub 2019 Apr 16.

Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University of Giessen, Giessen, Germany.

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http://dx.doi.org/10.1111/jvim.15503DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6524088PMC
May 2019

ECEIM consensus statement on equine metabolic syndrome.

J Vet Intern Med 2019 Mar 6;33(2):335-349. Epub 2019 Feb 6.

Equine Clinic, Internal Medicine, Faculty of Veterinary Medicine, Justus-Liebig-University of Giessen, Giessen, Germany.

Equine metabolic syndrome (EMS) is a widely recognized collection of risk factors for endocrinopathic laminitis. The most important of these risk factors is insulin dysregulation (ID). Clinicians and horse owners must recognize the presence of these risk factors so that they can be targeted and controlled to reduce the risk of laminitis attacks. Diagnosis of EMS is based partly on the horse's history and clinical examination findings, and partly on laboratory testing. Several choices of test exist which examine different facets of ID and other related metabolic disturbances. EMS is controlled mainly by dietary strategies and exercise programs that aim to improve insulin regulation and decrease obesity where present. In some cases, pharmacologic aids might be useful. Management of an EMS case is a long-term strategy requiring diligence and discipline by the horse's carer and support and guidance from their veterinarians.
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http://dx.doi.org/10.1111/jvim.15423DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6430910PMC
March 2019

An evaluation of serum gentamicin concentrations and bacterial susceptibility to gentamicin in equine practice.

Authors:
Andy E Durham

J Vet Intern Med 2018 May 25;32(3):1194-1201. Epub 2018 Mar 25.

Liphook Equine Hospital, Liphook, Hampshire, United Kingdom.

Background: Therapeutic drug monitoring and minimum inhibitory concentration (MIC) data allow more informed use of gentamicin.

Hypothesis/objectives: To measure peak and trough serum gentamicin concentrations in horses after a 6.6 mg/kg dose of gentamicin given IV and the MIC of gentamicin of bacteria for which gentamicin might be selected.

Methods: Retrospective analysis of hospital records. Peak and trough plasma gentamicin concentrations were measured after 6.6 mg/kg gentamicin IV in 339 hospitalized horses. The MIC of gentamicin was measured for 503 isolates from ambulatory practice and 33 from hospital practice. The distribution of gentamicin concentrations and MIC results were compared to current recommendations for MIC breakpoints.

Results: The median serum gentamicin concentration at 60 minutes after administration (C ) was 21.4 μg/mL with a distribution indicating that bacteria with MIC ≥2 μg/mL were unlikely to be exposed to sufficient gentamicin for effective killing. Approximately 90% of isolates from ambulatory practice and 36% of hospital isolates had MICs at or below breakpoints for susceptibility with most of the remainder unlikely to be responsive, even to higher IV doses.

Conclusions And Clinical Importance: Gentamicin at a dosage of 6.6 mg/kg IV is likely to be effective against the majority of infections encountered in ambulatory practice, but less effective in an equine hospital. Because there was a dichotomy of most bacteria as being clearly susceptible or clearly resistant to gentamicin, it appears unlikely that higher doses would have been more efficacious, especially in the hospitalized population in our study.
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http://dx.doi.org/10.1111/jvim.15078DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5980452PMC
May 2018

Therapeutics for Equine Endocrine Disorders.

Authors:
Andy E Durham

Vet Clin North Am Equine Pract 2017 Apr 9;33(1):127-139. Epub 2017 Feb 9.

Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK. Electronic address:

Equine endocrine disease is commonly encountered by equine practitioners. Pituitary pars intermedia dysfunction (PPID) and equine metabolic syndrome (EMS) predominate. The most logical therapeutic approach in PPID uses dopamine agonists; pergolide mesylate is the most common. Bromocryptine and cabergoline are alternative drugs with similar actions. Drugs from other classes have a poor evidence basis, although cyproheptadine and trilostane might be considered. EMS requires management changes as the primary approach; reasonable justification for use of drugs such as levothyroxine and metformin may apply. Therapeutic options exist in rare cases of diabetes mellitus, diabetes insipidus, hyperthyroidism, and critical illness-related corticosteroid insufficiency.
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http://dx.doi.org/10.1016/j.cveq.2016.11.003DOI Listing
April 2017

Endocrine Disease in Aged Horses.

Authors:
Andy E Durham

Vet Clin North Am Equine Pract 2016 Aug;32(2):301-15

Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK. Electronic address:

Aging horses may be at particular risk of endocrine disease. Two major equine endocrinopathies, pituitary pars intermedia dysfunction and equine metabolic syndrome, are commonly encountered in an aging population and may present with several recognizable signs, including laminitis. Investigation, treatment, and management of these diseases are discussed. Additionally, aging may be associated with development of rarer endocrinopathic problems, often associated with neoplasia, including diabetes mellitus and other confounders of glucose homeostasis, as well as thyroid, parathyroid, and adrenal diseases. Brief details of the recognition and management of these conditions are presented.
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http://dx.doi.org/10.1016/j.cveq.2016.04.007DOI Listing
August 2016

Insulin dysregulation and obesity: You are what you eat.

Authors:
Andy E Durham

Vet J 2016 07 16;213:90. Epub 2016 Mar 16.

Liphook Equine Hospital, Liphook, Hampshire GU30 7JG, UK. Electronic address:

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http://dx.doi.org/10.1016/j.tvjl.2016.03.010DOI Listing
July 2016

Surveillance focus: ragwort toxicity in horses in the UK.

Authors:
Andy E Durham

Vet Rec 2015 Jun;176(24):620-2

Liphook Equine Hospital, Forest Mere, Liphook, Hampshire GU30 7JG.

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http://dx.doi.org/10.1136/vr.h2817DOI Listing
June 2015

Viraemic frequencies and seroprevalence of non-primate hepacivirus and equine pegiviruses in horses and other mammalian species.

J Gen Virol 2014 Aug 9;95(Pt 8):1701-1711. Epub 2014 May 9.

Roslin Institute, University of Edinburgh, Easter Bush, Edinburgh, UK.

Non-primate hepacivirus (NPHV), equine pegivirus (EPgV) and Theiler's disease associated virus (TDAV) are newly discovered members of two genera in the Flaviviridae family, Hepacivirus and Pegivirus respectively, that include human hepatitis C virus (HCV) and human pegivirus (HPgV). To investigate their epidemiology, persistence and clinical features of infection, large cohorts of horses and other mammalian species were screened for NPHV, EPgV and TDAV viraemia and for past exposure through serological assays for NPHV and EPgV-specific antibodies. NPHV antibodies were detected in 43% of 328 horses screened for antibodies to NS3 and core antibodies, of which three were viraemic by PCR. All five horses that were stablemates of a viraemic horse were seropositive, as was a dog on the same farm. With this single exception, all other species were negative for NPHV antibodies and viraemia: donkeys (n=100), dogs (n=112), cats (n=131), non-human primates (n=164) and humans (n=362). EPgV antibodies to NS3 were detected in 66.5% of horses, including 10 of the 12 horses that had EPgV viraemia. All donkey samples were negative for EPgV antibody and RNA. All horse and donkey samples were negative for TDAV RNA. By comparing viraemia frequencies in horses with and without liver disease, no evidence was obtained that supported an association between active NPHV and EPgV infections with hepatopathy. The study demonstrates that NPHV and EPgV infections are widespread and enzootic in the study horse population and confirms that NPHV and potentially EPgV have higher frequencies of viral clearance than HCV and HPgV infections in humans.
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http://dx.doi.org/10.1099/vir.0.065094-0DOI Listing
August 2014

Metformin in equine metabolic syndrome: an enigma or a dead duck?

Authors:
Andy E Durham

Vet J 2012 Jan 31;191(1):17-8. Epub 2011 Aug 31.

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http://dx.doi.org/10.1016/j.tvjl.2011.08.003DOI Listing
January 2012

The role of nutrition in colic.

Authors:
Andy E Durham

Vet Clin North Am Equine Pract 2009 Apr;25(1):67-78, vi

The Liphook Equine Hospital, Forest Mere, Liphook, Hampshire, UK.

Nutritional intolerances manifesting as colic in the horse may be largely explained by divergence from the diet and ingestive behaviors to which the feral ancestors of modern domesticated equids had become accustomed and adapted. High-starch diets and abrupt dietary changes are probably foremost in the risk factors for diet-associated colic in the horse and have their basis in disruption of the stability of microbial populations resident within the equine hindgut. Although some general associations between colic and diet may be inferred from several epidemiologic studies, data derived from studies of single and specific disease processes associated with colic allow more effective practical application of corrective dietary management strategies in situations where colic risk is judged to be increased.
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http://dx.doi.org/10.1016/j.cveq.2008.11.003DOI Listing
April 2009