The findings bear out stories from vets who have described blind dogs acting completely normally – playing fetch and not bumping into things.
Dogs might be using their highly-sensitive noses to ‘see’ as well as to smell, a new study suggests.
A team of vets, including Dr Philippa Johnson from Cornell University in New York, discovered that vision and smell are actually connected in the brains of dogs – something not yet found in any other species.
The team performed MRI scans of a variety of dogs to map the olfactory bulbs (the brain’s part dealing with smell) and the occipital lobes (the brain’s visual processing area).
It revealed an “extensive pathway” connecting to the occipital lobe but also to the limbic system which is the part of the brain involved in behavioural and emotional responses.
The findings, published in the Journal of Neuroscience, suggest smell and vision in dogs are therefore integrated in some way – implying they may use scent to work out where things are.
Dr Johnson told Sky News partner NBC, that when humans walk into a room, they primarily use their sense of vision to establish who is there or how furniture is positioned. But dogs seem to integrate scent into their interpretation of their environment and how they are orientated in it.
She added: “One of the ophthalmologists at the hospital here said he regularly has owners that bring their dogs in, and when he tests their eyesight, they are completely blind – but the owners literally won’t believe him.
“The blind dogs act completely normally. They are able to play fetch. They can orientate around their environment, and they don’t bump into things. “