Just found a (free!) ebook on Project Gutenberg from around 1880. It's full of really short (like single paragraph short) stories about dogs. It's kind of fun to see people from over a hundred years ago telling the same kind of stories about their dogs (how smart they are, how much they understand, etc.) The author collected stories from many different sources, along with various beliefs bout dog heredity and then current scientific beliefs about dogs. Many of these are now extremely outdated, but seeing just how far science has advanced is fascinating and makes some of these old beliefs funny. (Such as teaching a dog something ensures it's puppies will inherit that teaching) If you download the larger file version there are black and white illustrations of different breeds and it is interesting to see how much some breeds have changed/not changed/don't exist anymore.
Since it's free, here's the link to the book:
I should note that while there are many entertaining stories, there are some stories that may be disturbing to modern readers, particularly some of the hunting stories, or descriptions of training methods.