Check out the book, Medieval Pets by Kathleen Walter-Meikel. I know for a fact that she answers all of your questions, but I am far away from my books and can't reference it. She also has a book called, Medieval Dogs, but if it's anything like Medieval Cats, (which I proudly own) it's less of a reference text and more of a fun look at mentions of cats in manuscripts with pretty pictures.

Edit: She does mention Petrarch loving his new dog for attacking the starving peasants who stumble up the hill looking for food, which is the most Petrarch sentiment ever.