EQUINE | Abstracts
The Prevalence of Uveitis in a Population
of Donkeys in the UK
Claire Bradley, Rachael Grundon, Philip G. Sansom
Background
Uveitis is reported to be a leading cause of blindness
in horses. Little work has been undertaken to date to
investigate whether donkeys are affected by a similar
disease prevalence.
Objectives
To investigate the disease prevalence of uveitis in a
population of donkeys in the UK.
Study design
Descriptive observational study.
Methods
An ophthalmic examination was performed on each
donkey, in a darkened stable. Each donkey underwent
slit lamp biomicroscopy, and direct and/or indirect
ophthalmoscopy. Fluorescein staining, STT1 and IOPs
were measured when deemed clinically necessary.
Pharmacological pupillary dilation was achieved using
1% tropicamide.
Results
A total of 207 donkeys were examined: 139 males
(67.1%) and 68 females (32.9%). Age range was 2‐37
years (median: 17 years, interquartile range: 9‐25 years).
Three donkeys (1.5%) were blind in one eye, and one was
monocular at the time of examination. Signs consistent
with either previous or current uveitis were identified in
eight eyes of six animals (2.9%). Clinical signs included
are as follows: miosis (n = 1), corpora nigra atrophy (n
= 6), anterior lens capsule pigment (n = 2), cataract (n
= 8), posterior synechiae (n = 3), lens subluxation (n =
1), vitreal changes (n = 2), peripapillary scarring (n = 3)
and phthisis bulbi (n = 1). Significant ocular pathology
precluded fundic examination in three eyes. Three out of
eight eyes (37.5%) were blinded by the pathology. The
risk of uveitis was found to increase with age (OR 1.1, CI:
1.01‐1.25) on univariable analysis (P = .046.).
Main limitations
Fluorescein staining, tonometry and Schirmer tear test
measurements were not performed on all donkeys.
Conclusions
The disease prevalence reported here is comparable to
that reported for horses in the UK. Larger prospective
studies are necessary to determine whether there is
a similar trend in disease prevalence in the donkey
population worldwide. In addition, further investigations
should aim to establish whether uveitis in donkeys is
similar to the ERU syndrome seen in horses.
https://beva.onlinelibrary.wiley.com/doi/abs/10.1111/evj.13257
12 • Equine Health Update •