When members of a humane society first spotted Allie zig-zagging down a street in Ontario, Canada, they thought she might have swallowed something toxic.

They took the stray labrador mix to a clinic where she was diagnosed with cerebellar hypoplasia -- a disorder that often leads to a death sentence for dogs.

As sweet as Allie was, though -- she was but three-months-old at the time -- they couldn't bear the idea of euthanizing her.

They contacted Rolling Dog Ranch, and, with word that the ranch had accepted her, a local campaign was mounted to pay her airfare. It raised $1,500, more than enough.

Allie is a floppy-eared lesson in persistence. She falls frequently, but gets right back up and doggedly continues to make her way to you. When she reaches you, she falls at your feet, which Smith believes is her way of making sure you stay still, so that she can stay by your side.

Of all the dogs I met at Rolling Dog Ranch -- and there are 40 of them there now, each inspirational in their own way -- Allie is the one that most inspired me. She's the canine version of the little engine that could, perseverance personified.

Here's a Rolling Dog Ranch video of her (click it twice to make it play) -- and how she gets from one side of a fence to the other.

 
(Tomorrow: A tale of two sisters)