Studies on the Visual Acuity of Dogs Using Shape Discrimination Learning

Abstract

The objective of this study was to determine the visual acuity of dogs. Three Shiba dogs (two females and one male) were trained to discriminate between a Landolt ring and an ordinary ring of equal size associated with feed. The left and right positions of the 2 targets were shifted according to the Gellermann series. After the dogs were fully trained, their visual acuity was determined by changing the size of the rings or the distance from the target. The dogs were subjected daily to 1 or 2 sessions which consisted of 30 trials each. The criterion for successful discrimination was 3 consecutive sessions with more than 21 correct choices (P<0.05, Chi-square test). The best scores of visual acuity in these three dogs were 0.23-0.33. These scores are slightly better than the results of some other domestic animals.