Effect of exercise on intraocular pressure (IOP) in dogs

Purpose: To investigate changes in intraocular pressure (IOP) during exercise in dogs. Methods: Fifteen healthy dogs of different breeds, with an average age of 2.9 years and an average body weight of 14.14 kg, underwent an exercise test on a motorized treadmill (pro- fessional canine treadmill, " Grillo, Modena, Italy) at the following speeds: 2.5 km/h for 15 min, 5.0 km/h for 20 min and 2.5 km/h for 10 min. IOP was measured with a Tonopen Vet (Medtronic, Solan–USA) at rest (T0), immediately after exercise (T1) and 1 h later (T2). IOP data are presented as the mean ` SEM. Student’s t-test was used to calculate signifi- cance between means before the exercise, immediately after the exercise and 1 h after the conclusion of the exercise. P < 0.05 was significant. Results: At rest (T0) the mean IOP was 12.86 mmHg in the right eye (OD) and 13.57 mmHg in the left eye (OS). Immediately after exercise (T1) the mean IOP was 12.64 mmHg in OD and 11.71 mmHg in OS. After the exercise was finished (T2) the values were 11.71 mmHg (OD) and 11.43 mmHg (OS). These changes in IOP were not significant immediately at the end of the exercise (P > 0.05), but they were significant 1 h later (P = 0.023 OD; P = 0.0088 OS). Conclusion: This study demonstrates, in a population of young adult dogs, that a period of dynamic exercise leads to significant changes in IOP.