Abstract:
BACKGROUND: Warmblood horses are a popular breed around the world for equestrian
sports. Previous studies have investigated ocular findings in other breeds of horses;
however, no studies exist for the Warmblood breed.
OBJECTIVES: To determine the prevalence of ocular abnormalities in a convenience
sample of Warmblood horses in South Africa and to determine if the prevalence of
lens and chorioretinal lesions increase with age.
STUDY DESIGN: Descriptive, observational study.
METHODS: Warmblood horses underwent a full ophthalmic examination which
included a Schirmer tear test (STT), tonometry, fluorescein dye testing, slit lamp biomicroscopy and indirect ophthalmoscopy. Age was categorised into three groups
namely <8 years old, 8–13 years old and 14+ years old for statistical analysis.
Prevalence of lens and chorioretinal lesions were compared between age categories.
RESULTS: One hundred and four horses (208 eyes) were examined. The age range was
5 months to 30 years (mean 11 years, standard deviation [SD] 6 years). Ocular
pathology was noted in 125 eyes (60.1%) and 79 horses (76%). The highest number
of lesions were noted in the choroid and retina, iris and lens. Chorioretinal lesions
were seen in 100 eyes (48.1%) and in 65 horses (62.5%). Iridial lesions were seen in
19 eyes (9.1%) and 12 horses (11.5%). Cataracts were seen in 19 eyes (9.1%) and in
13 horses (12.5%). The presence of total chorioretinal lesions (eye level [p = 0.002];
horse level [p = 0.004]), focal chorioretinal lesions (eye level [p = 0.004]; horse level
[p = 0.008]) and cataract (eye [p = 0.03]; horse level [p = 0.02]) were all shown to
statistically increase with age.
MAIN LIMITATIONS: A small sample size and limited geographic area.
Conclusions: There was a high prevalence of ocular pathology in this population of warmblood horses in South Africa. This reiterates the importance of an ocular examination as a part of routine health checks, as well as during pre-purchase examinations