Pressure inside the eyes of endurance horses fluctuate during a race, especially so in those finishing with faster times, research has shown.
The findings of the American study have been published in the journal, Veterinary Ophthalmology.
Rachel Albaugh, from Kansas State University, and fellow researchers Susan Kell, Zhining Ou and Nora Bello set out to assess intraocular pressure – that’s pressure inside the eye – of conditioned equine athletes in endurance rides and document any changes with exercise.
They also wanted to assess associations between eye pressure and heart rate, as well as with other subjective physical parameters.
Readings were collected on a total of 69 horses taken during 50-mile endurance rides.
The readings were made at five different competitions at three different locations. Several horses competed in more than one ride, meaning the researchers ended up with data from 80 horse-ride combinations.
Internal eye pressure was measured using a TonoVet tonometer in both eyes of each horse prior to, at two time points during, and immediately after endurance competitions.
Heart rates and subjective veterinary scores were recorded on ride cards at each time point.
For horses with shorter finishing times, eye pressure was lower at the end of endurance exercise, although upward fluctuation was apparent during the ride.
For horses with longer finishing times, eye pressure did not change significantly from baseline to the end of exercise.
Responses also differed between horses awarded “Best Condition” relative to other horses, whereby the latter, but not the former, showed an overall decrease in eye pressure by the end of exercise.
There was no evidence for any association between eye pressure and heart rate, nor between internal eye pressure and subjective clinical scores.
Allbaugh, R. A., Keil, S. M., Ou, Z. and Bello, N. M. (2014), Intraocular pressure changes in equine athletes during endurance competitions. Veterinary Ophthalmology. doi: 10.1111/vop.12182
The abstract can be read here.