In Kent Rasmussen's _Mark Twain for Dog Lovers_ (2016), Rasmussen relates
that Jean's dog Fix bonded with Ossip, Clara's husband, shortly after they
arrived back at Stormfield a few days before her father's death.  There is
no description of the dog's reaction to Clemens's death.  After Clemens
died, Clara and Ossip took Fix back to Munich, Germany with them.
Unfortunately, he got out in the street there and was struck by a car.
Diligent care failed to save him and Fix died with Ossip by his side.
There is a photo of Fix and Ossip at Stormfield in Clara's book _My Husband
Gabrilowitsch_, (1938).

Barb