The smartest dog on earth, the border collie "Chaser" is dead is dead at 15 years. Dr. John W. Pilley, a professor emeritus of psychology at Wofford College who taught Chaser over 1000 nouns, died last year at 89. More here.

Chaser learned to identify 1000 objects (fuzzy toys mostly) by name. Chaser was not unique. “What we would really like people to understand about Chaser is that she is not unique,” Ms. Bianchi [one of Dr. Pilley's daughters] said. “It’s the way she was taught that is unique. We believed that my father tapped into something that was very simple: He taught Chaser a concept which he believed worked infinitely greater than learning a hundred behaviors.”

In 2013, Dr. Pilley published his findings that explained that Chaser was taught to understand sentences containing a prepositional object, verb and direct object.

We now know so much more about how dog brains work than we did 50 or 100 years ago. Everything is being investigated. French scientists have figured out why your dog finds a stranger's crotch more interesting than its owner's. (Frontiers in Zoology

https://www.cbsnews.com/video/the-smartest-dog-in-the-world/