Introduction

The incidence of glaucoma in cats is less than dogs, but it is important to maintain IOP within normal reference values during and after the surgery.

Objectives

To assess the effect of intramuscular ketamine­midazolam administration on IOP in normal feline eyes.

Methods

Fifteen adult domestic short-haired cats ranging in age from 14–20 months were used for this study. The treatment group (n=8) received intramuscular (IM) ketamine 10 mg/kg in combination with midazolam 0.1 mg/kg and distilled water was injected IM for the control group (n=7). Baseline IOP was measured by using rebound tonometer. Then at the time of 10, 20, 30, 45, 60, 90, 120 minutes, and 24 hours after administration, the IOP of all eyes in both groups measured.

Results

The baseline mean±SD IOP values in treatment and control groups were 19.57±3.32 mm Hg and 17.35±1.86 mm Hg, respectively. In the treatment group mean IOP increased at T10, T45, and T60 after drug administration but this increase was not statistically significant (p>0.13). In the control group IOP did not change except a mild decrease at T10 (p>0.11). A comparison between the two groups, revealed that IOP significantly altered at T10, T45, T60, T90 and T120. There was no significant difference between control and treatment group at baseline and 24 hours after drug administration.

Conclusions

Intramuscular administration of ketamine-midazolam combination as a pre-anesthetic did not increased IOP significantly in clinically healthy cats.