I've heard of Labernese being bred and used as guide dogs.
Just a bit on that subject --
A lot of guide dog orgs. crossbreed dog breeds that traditionally throw big litters with other dog breeds that throw big litters. This is so they're able to raise as many as possible in a a timely fashion. I'm not saying it's right or wrong since I haven't decided for myself yet... I know that a lot of puppies raised in the program I was in didn't make it to final graduation, so just by the law of statistics you'd have to start out with a huge number of puppies to get maybe 10 guide dogs.
There are a lot of smaller orgs out there trying to place dogs they think are better suited for the jobs even though they don't throw large litters. Personally, I think we could do better than labs for guide dogs for the blind. I am far from saying they're not great dogs as lately I've been really wanting to go adopt one from our shelter because I'm missing my Abby-girl, but I'm saying that there are dogs out there that mature quicker mentally and will learn quicker. What about working bred BCs for the really active blind person? But I'll stop before I get really OT.