Effects of alfaxalone, medetomidine, and xylazine on intraocular pressure in domestic pigeons (Columba livia domestica).

Abstract

Objective: To evaluate the effects of alfaxalone, medetomidine, and xylazine on intraocular pressure (IOP) in domestic pigeons (Columba livia domestica).

Animals studied: Eight 12-month-old pigeons (16 eyes).

Procedures: The pigeons were randomly assigned to three treatment groups (10 mg/kg of alfaxalone, 0.2 mg/kg of medetomidine, or 10 mg/kg of xylazine) with a 7-day washout period. The IOP was measured using a rebound tonometer and calibrated using the formula y = 0.439x + 2.059, where y is the tonometric IOP and x is the actual IOP.

Results: All three drugs significantly reduced IOP. Alfaxalone led to the least reduction at 5.2 mm Hg, medetomidine reduced IOP to 12.5 mm Hg, whereas xylazine resulted in the greatest reduction at 15.3 mm Hg. Alfaxalone achieved its maximum IOP reduction in 6 min, whereas medetomidine and xylazine required 95 and 115 min, respectively. Both alpha-2 agonists, medetomidine, and xylazine, showed a prolonged duration of effect and a greater reduction in IOP than those of alfaxalone. All three medications provided adequate sedation without any discernible adverse effects.

Conclusions: The findings revealed the varied effects of these drugs on IOP in pigeons, potentially providing valuable insights that could be useful for broader applications in veterinary medicine.