Last year Sharlene and Mark Cannon observed that their enormous dog always insisted on walking and sitting on their five-year-old son’s right side, in a manner similar to a guide dog, Metro.co.uk reports.
So the British parents decided to get their son’s eyesight checked out.
It turned out that he had a severe astigmatism in his right eye, leaving his vision completely blurred.
"It’s incredible to think that Mark had this problem with his eye since birth," Mark's mother said, "and Alfie was the only one who spotted it. If it hadn’t been caught when it was, he could have gone blind."
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