It's not only a matter of length. The house in that poor piggie's cage takes up all of the "across" room so they really can't run around all that much. They are not "lazy", they are cramped and have the good sense to realize it.
We are as gods to the beasts of the fields. We order the time o' their birth and the time o' their death. Between times, we ha' a duty. - Terry Pratchett.
"Men have forgotten this truth", said the fox, "But you must not forget it. You become responsible, forever, for what you have tamed. - Antoine de Saint-Exupéry