A dog whose owner didn't know for NINE MONTHS that her pooch was totally blind has been declared a "medical mystery".
Border Collie Dave "never puts a foot wrong" despite his blindness - leaving top vets completely baffled by his condition.
Owner Jane Downes, 69, said that there were no clues that Dave couldn't see, despite having owned him for almost a year before making the discovery.
A top UK vet has declared Dave a "medical mystery" after confirming that the pooch - believed to be between five to seven years old - is fully blind.
Jane, from Waterbeach, Cambs, said: "No one's got any answers. It's just a conundrum.
"It's just really strange. He's a blind dog that can see.
"Maybe it's a sixth sense, who knows?
"He had everyone fooled - even me as his owner I was fooled for nine months."
Jane bought Dave from an animal rescue centre in February 2020, when no issues were raised regarding his sight - even after a check-up at the local vet.
Jane added: "He jumped into the back of the car and I brought him home.
"A couple of people said he had funny eyes but I just thought he's got beautiful eyes.
"On a couple of occasions he walked into things but I put that down to him being a sheepdog who more than likely lived in a barn rather than a house."
"He wouldn't put a foot wrong. He would come back when you called him."
But in December, Dave stumbled over a step at a pet shop in Cambridge, where the owner suggested to Jane that her dog might be blind.
She took Dave to a specialist vet, where they finally revealed that he was totally blind and his retinas had never developed, meaning he was blind from birth.
After the diagnosis, Jane called on the help of Cambridge University's David Williams, a top veterinary ophthalmologist, who carried out two obstacle course challenges and a retina test before confirming the diagnosis.
He told a local newspaper: "I see a lot of blind dogs and they all bump into objects in a way that Dave didn't - so at present he is a medical mystery!
"Just because I've been doing this for 33 years, it doesn't mean I've seen everything, and this I can't explain.
"In life you like to think you know everything, but that's not always the case."
Dave enjoys running around at home with his new brother Sammy, a two-year-old border collie, who joined the family in October last year.
Jane, who lives with husband Mick, 78, said that Dave still lives a happy and full life.
She explained: "He goes straight to his food. He chases other dogs around even though he can't see them.
"He can jump into the boot of my car. He walks around puddles."
"On the very rare occasion, he walks into something he just shrugs it off and carries on."
Dave's only limit is his fear of going into the sea - but Dave doesn't know if this is due to his blindness or a possible traumatic experience as a puppy.
*Video filmed 21st September 2021.