Do guide dogs know their owners are blind? That's something we've always wondered. It's amazing to watch service dogs perform complicated tasks — like knowing when to cross a street or picking the right medicine to bring to their owners — but do they understand why they do what they do?
Not much research has been conducted on this topic, but there is one study from February 2008 that was published in the journal Animal Cognition that sought to answer the question of whether dogs whose owners were blind asked for food differently than pet dogs whose owners could see. One common behavior of dogs when asking for food is to look back and forth between their owner and food bowl, as if to say, "Please fill this." The French researcher who wrote the paper, Florence Gaunet, wanted to know if guide dogs whose owners were blind used the same visual cues to show that they wanted something. If guide dogs still frequently looked to their owners, it would signal that they did not realize their owners were blind.
Gaunet found that guide dogs still alternated gazes between their owners and food, which seems to indicate that these dogs did not understand that their owners were blind. Interestingly, Gaunet noted that guide dogs were more likely to exhibit "sonorous mouth licking," so it seems like the guide dogs ultimately realized their owners responded better to sounds. Seven of the nine guide dogs noisily licked their mouths compared to only two of the nine pet dogs.
Regardless of the study's results, one thing's for sure: Dogs would still absolutely adore their owners even if they realized they were blind. And of course, being blind doesn't mean the owners love their pets less. In fact, we would argue that the bond between people with disabilities and their guide dogs is perhaps stronger than some people with their pets because owners with special needs sometimes rely on their service animals to keep them alive — and we couldn't think of a species more willing to help their humans.