Looks like this turned into the literary dog thread. I don't know any such dogs but am planning to read the James Herriot books at sometime in the not-too-distant future so I'm sure I'll meet some that way.
Oh, I take it back. I'm reading the Mitford series this year with a group of women on Booktube - these are Christian novels about life in a small town in North Carolina, and the main character is Father Tim, an Episcopalian priest. He has a big dog named Barnabus. Could be part poodle but definitely a mixed breed... large, shaggy, black. I'm starting the seventh book in the series, In This Mountain.
In the nonfiction about the gold rush, The World Rushed In, the man whose diary and letters we've been reading has finally decided to head home from California to New York. He'll be going through Panama. I'm about to start the last chapter of the book.