Why aren't guide dogs more popular in Japan?

I have always wondered why guide dogs aren't used as much in Japan as they are in Europe. You would think they would be a natural fit given Japan's love of dogs. But you rarely see a visually impaired person using a guide dog in Japan. I worked at a relatively large school for the blind in Japan and never once saw a guide dog at the school during my time there.

White canes are more common. Japan does have Braille blocks, aka tactile paving, which may be why guide dogs are seen as less of a necessity. I don't know. A search online suggested that there are less than 1000 guide dogs used in Japan and more than 1.6 million people with visual impairments of which about 300,000 people are legally blind. 

The reason I am contemplating this once again today is because it is International Guide Dog Day 国際盲導犬の日. It falls on the last Wednesday of April annually. Because it falls on Showa Day this year, there may not be as many events on in Japan as normal, but usually the Japan Guide Dog Association marks the day in some way.