The effects of different anesthetic agents on short electroretinography protocol in dogs

The purpose of this article was to investigate the effects of sedatives and general anesthetics, such as tiletamine-zolazepam, medetomidine, and isoflurane on the short ERG protocol. Six healthy mongrel dogs were assessed by a convenient short ERG protocol with the owners' consent. The amplitudes of a-wave and b-wave, as well as the implicit time of ERG under different anesthesia statuses, were recorded and analyzed. The amplitudes of ERG waves were not significantly different between tiletamine-zolazepam and medetomidine groups, except in b-wave after 5 min dark adaptation (140 +/- 42 microV in tiletamine-zolazepam and 101 +/- 32 microV in medetomidine, p<0.01). The amplitude of ERG recorded in isoflurane (5 +/- 3 microV of a-wave and 12 +/- 6 microV of b-wave under light adaptation; 41 +/- 19 microV of b-wave after 1 min dark adaptation; 28 +/- 15 microV of a-wave and 58 +/- 32 microV of b-wave after 5 min dark adaptation) were significantly different from tiletamine-zolazepam (8 +/- 2 microV of a-wave and 24 +/- 9 microV of b-wave under light adaptation; 117 +/- 44 microV of b-wave after 1 min dark adaptation; 59 +/- 18 microV of a-wave and 140 +/- 42 microV of b-wave after 5 min dark adaptation), except in a-wave after 1 min dark adaptation (39 +/- 13 microV in tiletamine-zolazepam and 34 +/- 17 microV in isoflurane). Comment-General anesthesia had significantly lower amplitudes in the dark-adapted group compared with the sedation group. Therefore, tiletamine-zolazepam is a desirable choice for the short ERG protocol in dogs.