We recently watched an episode of the PBS show Nova called Dogs Decoded. It is currently available on Netflix watch instantly or for free at Top Documentary films
It’s absolutely fascinating. Nova has set up a website with some interactive features.
They show a few Blenheim and tricolor cavaliers, but for the most part, this is an astounding look at dogs in general and the special relationship between humans and canines.
One of the segments dealt with breeding experiments and emphasized how important it is to only use the very best temperaments in a breeding program. While we certainly didn’t like to see how the foxes were treated, the scientific results are enlightening.