Association between owner-perceived clinical signs and the presence of equine glandular disease on endoscopy

Background: Reporting clinical symptomology of equine glandular
gastric disease (EGGD) and trying to establish clinical significance is
challenging. Most signs are nonspecific, subjective and often ownerperceived. This is complicated further by the fact that some horses
with EGGD may not demonstrate clinical signs, and there is currently
little evidence to support an association between these signs and
the presence of EGGD on gastroscopy.
Objectives: To determine if there is an association between ownerperceived clinical signs and the presence of EGGD on gastroscopy.
Study design: Multicentre prospective cohort study.
Methods: A questionnaire detailing the observation of relevant clinical signs was completed by horse-owners immediately prior to the
horse undergoing gastroscopy. The study included 67 horses with
EGGD and 78 horses with a normal stomach. Horses with concomitant squamous lesions were excluded. The data were analysed using
binary logistic regression modelling.
Results: All EGGD lesion types and severity were represented in the
study. With the exception of resentment of grooming, none of the
clinical signs under investigation were significantly associated with
the presence of EGGD. Resentment of grooming was associated
with reduced odds of the presence of EGGD (OR = 0.32, 95% CI
= 0.13–0.78) and was therefore not likely to be clinically relevant.
The distribution of clinical signs observed in horses both with and without EGGD was remarkably similar and may be explained by an
observer-expectancy effect resulting in confirmation bias.
Main limitations: Horse-owners were relied upon to report clinical
signs, and therefore they may not have been an accurate reflection
of the actual signs displayed by the horse.
Conclusions: Observation and reporting of characteristic clinical
signs of EGGD by owners is not a useful determinant of whether or
not a horse is affected by EGGD. Further investigation into the association between clinical signs of EGGD and specific lesion types or
severity may be warranted.
Ethical animal research: Ethical approval obtained by the RVC Social
Sciences Research Ethical Review Board (URN SR2017-1332).
Informed consent: Informed consent was obtained for all horses included in the study.
Competing interests: None declared.
Sources of funding: None.