Effect of tiletamine-zolazepam on the intraocular pressure of the dog

Objective: To determine the effect of tiletamine-zolazepam (TZ) on canine intraocular pressure (IOP). Animals studied: Six healthy dogs without ocular abnormalities were used in this study. Procedures: The study was carried out as a crossover experimental trial with a 7-day interval between treatments. TZ combination was administered intravenously (IV) at a dose of 5, 10, and 20mg/kg (TZ5, TZ10, and TZ20, respectively). Following preanesthetic baseline readings of IOP, each dog received IV TZ and then the IOP values were measured every 10min for 40min in all treatments. Results: The baseline IOP values (mean±standard deviation) for TZ5, TZ10, and TZ20 were 12.7±0.8, 14.4±1.2, and 15.3±1.7mmHg, and each IOP changed to 11.1±1.1, 13.1±1.4 and 13.5±1.7mmHg after intravenous administration of each TZ treatment, respectively. However, there were no statistical differences between baseline and post-treatment values. Conclusions: The TZ combination had no clinically significant effect on IOP of the dog. This could be an option for induction or surgical procedures in dogs with ophthalmic problems when an increase in IOP is undesirable.