Via Andrew Sullivan, part of an interview with then-Cardinal Ratzinger:

At any rate, we can see that [animals] are given into our care, that we cannot just do whatever we want with them. Animals, too, are God’s creatures, and even if they do not have the same direct relation to God that man has, they are creatures of his will, creatures we must respect as companions in creation and as important elements in the creation.

As far as whether we are allowed to kill and to eat animals, there is a remarkable ordering of matters in the Holy Scripture. We can read how, at first, only plants are mentioned as providing food for man. Only after the flood, that is to say, after a new breach has been opened between God and man, are we told that man eats flesh… Nonetheless…we should not proceed from this to any kind of sectarian cult of animals. For this, too, is permitted to man. He should always maintain his respect for these creatures, but he knows at the same time that he is not forbidden to take food from them. Certainly, a sort of industrial use of creatures, so that geese are fed in such a way as to produce as large a liver as possible, or hens live so packed together that they become just caricatures of birds, this degrading of living creatures to a commodity seems to me in fact to contradict the realtionship of mutuality that comes across in the Bible.

Also, turns out the pope is a cat person, so he has good taste too.