'Instructables' member 'aimzzz' found out about Luisa, a puppy born without any front legs. To help her, aimzzz decided to make a 3D printed wheelchair that she could easily be trained to use. In fact, aimzzz was so moved by the plight of the dog that he adopted her and also decided to make his wheelchair project open-source so that it would benefit other dogs in similar situations. You can find the complete instructions for the project as well as the 3D files here and you can check out Luisa's German Facebook page here.
Everything You Need To Build The Chair
Adjusting The Chair