I first read Watchers back in the early nineties and last month I re-read it.
The ending differed a lot from my recollection, in the new version they settle down with a baby and the special dog and a tranquil life... the end.
This left me somewhat nonplussed, in my memory of the book there was a chapter featuring a gathering/house party of owners of similar dogs.
The humans all sit and chat, the dogs did the same using modified computers set up for paws, the animals spelled out their problems etc.
Was the book revised at some point or did Dean Koontz perhaps do a short story with the same characters and I've got them mentally merged?.
Update: I've now got a full copy of the book and I've taken a good look at the ending, it matches the details supplied by Fuzzy Boots in the answer.
However I still suffer from a Mandela Effect with the ending - I'm convinced that, at some time, I read where the dog families had gathered around various modified computers and there was like older dogs passing on learning to the pups via the PC screens, then later we had the Einstein final scene