There's no shortage of material out there on how best to train dogs in the basics: to sit, stay, and come when called -- but some of the most valuable lessons on finding happiness through life's difficulties just might be the ones they can teach us in return.

All too often, pets with disabilities are the last to be adopted, deemed undesirable for the special care they require. Thankfully, however, there are people like Gritta Götz, who runs an animal sanctuary in Lanzenhainer, Germany, there to give them a chance to live their lives to the fullest. 

And boy, do they ever.

Gritta told The Dodo that she originally had just one dog, but through her volunteering with rescue organizations, she began opening her home to some of their needier pets. Today, more than two dozen formerly-unwanted dogs that live on her rural sanctuary, eight of which are confined to wheelchairs.

They may be a little slower than their four-legged counterparts in this spirited game of fetch, but that doesn't keep them from trying.