Besides downloading more than 250 books so far from Kindle, most of them classics for free, I've bought and am reading a few that cost $2.99 or less and one just downloaded for $7.95. Keeping costs down, but then two days ago I spent over $30 in the bookstore!
I'm now re-reading and enjoying Travels with a Donkey in the Cevennes by Robert Louis Stevenson, in which the author roams through mountains in France with his pack animal, a little donkey he names Modestine.
Another travel book that I've read a couple of times is Travels with Charley in Search of America: (Centennial Edition) by John Steinbeck, who motored across America in the 1960 with his dog, a standard poodle named Charley.
Wish I knew more books about traveling with a pet or animal. Do you know of any?