An electroretinogram protocol for toxicological screening in the canine model.

A five-step electroretinogram protocol was developed for the dog to be used as a painless screening test for ocular effects of drugs or pesticides. Standard conditions of frequency band width, stimulus intensity, dark adaptation time and non-confounding anesthesia method were selected to allow analysis of wave components. The protocol demonstrated an acceptable level of inter-subject variability for compiling an age appropriate database, and for the detection of possible retinal component toxicities in chronic dog studies. This electrophysiologic procedure may serve to corroborate biochemical, clinical and pathology data, in establishing a compound's no-observable-effect-level (NOEL).