The effects of intravenous alfaxalone with and without premedication on intraocular pressure in healthy dogs.

The objective of this study was to investigate the effects of intravenous alfaxalone with and without premedication on intraocular pressure (IOP) in healthy dogs. Thirty-three dogs were randomized to receive 1 of 3 treatments: acepromazine [0.03 mg/kg body weight (BW)] with butorphanol (0.2 mg/kg BW) intramuscularly (IM), followed by intravenous (IV) alfaxalone (1.5 mg/kg BW); dexmedetomidine (0.002 mg/kg BW) with hydromorphone (0.1 mg/kg BW) IM, followed by alfaxalone (1 mg/kg BW) IV; and saline 0.9% (0.02 mL/kg BW) IM, followed by alfaxalone (3 mg/kg BW) IV. Intraocular pressure (IOP) was measured at baseline, 15 min, and 30 min after premedication, after pre-oxygenation, after administration of alfaxalone, and after intubation. After induction and after intubation, the IOP was significantly increased in all groups compared to baseline. While premedication with acepromazine/butorphanol or dexmedetomidine/hydromorphone did not cause a significant increase in IOP, the risk of vomiting and the associated peak in IOP after dexmedetomidine/hydromorphone should be considered when selecting an anesthetic protocol for dogs with poor tolerance for transient increases in IOP.