Factors influencing development and outcome of equine gastrointestinal disease

Bishop, Rebecca Coco

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https://hdl.handle.net/2142/113244 Copy

Description

Title

Factors influencing development and outcome of equine gastrointestinal disease

Author(s)

Bishop, Rebecca Coco

Issue Date

2021-06-09

Director of Research (if dissertation) or Advisor (if thesis)

McCoy, Annette M

Committee Member(s)

• Gutierrez Niberyo, Santiago
• Wilkins, Pamela A
• Andrews, Frank

Department of Study

Vet Clinical Medicine

Discipline

VMS-Veterinary Clinical Medcne

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

• gastrointestinal disease
• horse
• equine
• colic
• ulcer
• peptic ulcer
• EGUS
• omeprazole
• PPI
• predictive model

Abstract

Gastrointestinal diseases are a common cause of morbidity and mortality in horses. Colic refers to clinical signs attributed to abdominal pain in horses. The pathology underlying colic is diverse, which makes accurate prediction of survival challenging. Equine Gastric Ulcer Syndrome (EGUS) is common in horses and can be both a cause and associated comorbidity of colic and colic treatment. EGUS and other gastrointestinal diseases have significant implications on horse welfare and performance, as well as a negative economic impact on the equine industry. The two investigations comprising this thesis address separately the prognosis of surgical colic and efficacy of prophylactic medications for prevention of EGUS. Objective 1: Horses requiring an exploratory laparotomy for treatment of colic may have different risk factors for non-survival than a broader equine colic population, including horses with colic responsive to medical management. Development of accurate pre-operative predictive models in a surgical colic population may assist clinicians in prognosticating outcomes for these patients. The objective of this study was to compare the predictive performance of cohort-specific versus previously published univariate and multivariate models for survival in horses undergoing exploratory laparotomy for treatment of colic. Medical records from a single referral hospital were reviewed retrospectively for all horses undergoing exploratory laparotomy over a 12-year period. Preoperative, perioperative, and postoperative data of 302 horses were obtained. Cohort-specific models to predict outcome were developed by backwards stepwise generalized multiple linear regression. Cohort-specific and previously published models were applied to cohort data to predict outcome. Sensitivity, specificity, positive and negative predictive values (PPV, NPV), and accuracy for prediction of short-term survival were calculated. Short-term survival rate was 51.7%. Perioperative factors associated with short-term survival in the population studied included age, sex, admission heart rate, mucous membrane appearance, ionized calcium, blood pH, and total solids. Predictive models derived from cohort-specific data outperformed models developed from broader colic populations in previous studies, suggesting that population-specific factors contribute to patient survival. Findings support continued use of commonly considered variables in clinical assessment of surgical colic patients. However, no single parameter or published predictive model performs adequately to replace the value of clinician judgement. Objective 2: Hospitalized horses may be exposed to known risk factors for EGUS, including fasting and non-steroidal anti-inflammatory drug (NSAID) administration, putting them at high risk for formation of both squamous (ESGD) and glandular (EGGD) gastric ulcers. Prophylactic anti-ulcer medication selection is complicated by differences in etiology and response to treatment of these two types of ulcers. This study tested the hypothesis that prophylactic administration of omeprazole or sucralfate would be equally effective for prevention of EGUS in horses exposed to a combined fasting/NSAID ulcer induction model. Fourteen adult horses with baseline ESGD and EGGD scores ≤ 2 were included in a randomized crossover experimental design. Horses received either omeprazole or sucralfate while undergoing the fasting/NSAID protocol, allowed an 8-week washout period, and then administered the alternate treatment. Serial gastroscopy, ultrasound, and hematology documented treatment effects. ESGD and EGGD worsened over time under both treatments. However, post-treatment EGGD scores were significantly higher (worse) for horses receiving sucralfate compared to omeprazole. Healthy horses developed severe ESGD and EGGD within 5 days of exposure to fasting/NSAID protocol; the use of omeprazole was superior to sucralfate for mitigating the formation of gastric ulcers in this study.

Graduation Semester

2021-08

Type of Resource

Thesis

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http://hdl.handle.net/2142/113244

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Copyright 2021 Rebecca Coco Bishop

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