EQUINE | Abstracts
Serial evaluation of resting and exercising over-
ground endoscopic examination results in young
Thoroughbreds with no treatment intervention
C. L. McGivney J. Sweeney K. F. Gough E. W. Hill L. M. Katz
First published: 12 July 2018
Background
We hypothesised that grade/appearance for upper
respiratory tract (URT) disorders identified at the first
overground endoscopy (OGE) examination would
vary at subsequent examinations.
Objectives
To compare OGE examinations from horses evaluated
on at least two occasions under similar exercise
conditions without treatment intervention.
Study design
Retrospective cohort.
Methods
Pre‐exercise and exercising OGE recordings
from Thoroughbred horses undergoing multiple
examinations under similar exercise conditions were
reviewed, with the first two recordings for each horse
statistically evaluated. Paired Wilcoxon signed‐rank
tests were used to assess differences in exercise and
physiological parameters between examinations.
Z‐tests were used to assess the proportion of
changes in URT disorder grade/appearance between
examinations. A McNemar's test was used to
compare the proportion of horses with each disorder
at each examination. Test–retest reliability across
examinations was assessed using Spearman's ρ, and
ordered logistic regression used to explore temporal
effects on repeatability. Lattice plots were constructed
16
to view variability in disorders over time.
Results
Seventy‐eight horses (median age 2.4 years) with 195
resting endoscopic examinations including 72/78
horses with 179 pre‐exercise and exercising OGE
examinations were evaluated. Median time between
examinations was 226.5 days with no differences
between exercise and physiological parameters.
Grades significantly varied between examinations for
all disorders, and in particular for palatal instability
(PI) and epiglottic grade at rest. A temporal link
between examination interval and disorder grade
change was identified for PI and resting arytenoid
asymmetry.
Main limitations
OGE re‐examinations within a shorter, more
consistent time‐frame would allow determination of
intrahorse variability. The sample size was inadequate
to conclusively establish temporal links between
disorders and time between examinations.
Conclusions
Variability for most URT abnormalities identified with
OGE should be considered when making therapeutic
decisions based on a single examination and may
partially explain development of additional URT
conditions after surgical intervention.
• Equine Health Update •
https://doi.org/10.1111/evj.12994