Effects of acepromazine on intraocular pressure, anterior chamber depth in horses: A prospective randomized controlled study

Abstract

This study aimed to evaluate the effects of acepromazine on intraocular pressure (IOP), anterior chamber depth (ACD), cardiovascular and respiratory rates in horses. In a prospective, randomized, controlled trial, twelve horses were equally allocated randomly into two groups: treatment and control (n = 6 each). Horses of the treatment group received 0.1 mg/kg body weight (bwt) of acepromazine intravenously, while those in the control group received 0.4 mL/100 kg bwt of 0.9% sodium chloride intravenously. IOP, ACD, heart rate, and respiratory rate were recorded before (T0) and then at T10, T20, T30, T40, T50, T60, T70, T80, and T120 min post-treatment. Acepromazine induced a significant drop in IOP and ACD (P < 0.05) between T10 and T40 in comparison with the saline group. Regarding heart rate, the acepromazine group's heart rate noticeably increased (P < 0.05) from T10 to T150, while their respiratory rate significantly decreased when compared to the saline group (P < 0.05). In conclusion, with proper monitoring of the horse's respiratory and cardiac functions, acepromazine can be used as a sedative drug for intraocular surgery. The findings of this study on healthy horses may not be extrapolatable to findings in those with ophthalmic lesions. Therefore, further studies with larger populations, different dosage regimens, and longer monitoring intervals are recommended for horses with ophthalmic diseases to better understand the safety profile of the drug.