Diagnostic accuracy of blood sucrose as a screening test for equine gastric ulcer syndrome (EGUS) in weanling foals

Abstract

BackgroundEquine gastric ulcer syndrome is an important cause of morbidity in weanling foals. Many foals are asymptomatic, and the development of an inexpensive screening test to ensure an early diagnosis is desirable. The objective of this study was to determine the diagnostic accuracy of blood sucrose for diagnosis of EGUS in weanling foals.Results45 foals were studied 7 days before and 14 days after weaning. The diagnostic accuracy of blood sucrose for diagnosis of gastric lesions (GL); glandular lesions (GDL); squamous lesions (SQL) and clinically significant gastric lesions (CSL) at 45 and 90 min after administration of 1 g/kg of sucrose via nasogastric intubation was assessed using ROC curves and calculating the AUC. For each lesion type, sucrose concentration in blood was compared to gastroscopy; and sensitivities (Se) and specificities (Sp) were calculated across a range of sucrose concentrations. Cut-off values were selected manually to optimize Se. Because of concerns over the validity of the gold standard, additional Se, Sp, and lesion prevalence data were subsequently estimated and compared using Bayesian latent class analysis. Using the frequentist approach, the prevalence of GL; GDL; SQL and CSL before weaning was 21; 9; 7 and 8% respectively; and increased to 98; 59; 97 and 82% respectively after weaning. At the selected cut-off, Se ranged from 84 to 95% and Sp ranged from 47 to 71%, depending upon the lesion type and time of sampling. In comparison, estimates of Se and Sp were consistently higher when using a Bayesian approach, with Se ranging from 81 to 97%; and Sp ranging from 77 to 97%, depending upon the lesion type and time of sampling.ConclusionsBlood sucrose is a sensitive test for detecting EGUS in weanling foals. Due to its poor specificity, it is not expected that the sucrose blood test will replace gastroscopy, however it may represent a clinically useful screening test to identify foals that may benefit from gastroscopy. Bayesian latent class analysis represents an alternative method to evaluate the diagnostic accuracy of the blood sucrose test in an attempt to avoid bias associated with the assumption that gastroscopy is a perfect test.

Inter‐observer variability of two grading systems for equine glandular gastric disease

“…21,22 Interobserver agreement for the presence of EGGD has been shown to be weak (κ = 0.42), with higher agreement (κ = 0.56) on whether lesions were deemed clinically significant. 23 amongst non-diplomates. The use of a number may reflect the original EGUS scale which respondents may be more familiar with.…”

“…Ordinal scales have also been shown to have poor inter‐rater agreement when assessing lameness in horses 21,22 . Inter‐observer agreement for the presence of EGGD has been shown to be weak (κ = 0.42), with higher agreement (κ = 0.56) on whether lesions were deemed clinically significant 23 …”

Welfare Assessment in Calves Fattened According to the “Outdoor Veal Calf” Concept and in Conventional Veal Fattening Operations in Switzerland

“…Previous disease was associated with a higher prevalence of gastric lesions [ 34 ]. Foals examined before and after weaning had a higher prevalence of gastric lesions after weaning, suggesting that the stressful event of weaning promotes lesion formation [ 35 , 36 ]. In the present study, the prevalence of abomasal lesions, assessed as indicators of stress, did not differ between IF and CF.…”

Highlights of recent clinically relevant papers

“…This study by Michael Hewetson and colleagues based in the UK, Finland, Germany, Australia and South Africa aimed to determine the diagnostic accuracy of blood sucrose as a screening test for equine gastric ulcer syndrome (EGUS) in weanling foals .…”