Flash was a German Shepherd Dog actor.
Call The Mesquiteers 1938
as Hawkshaw - Tim's Dog (as Flash)
Wild Waters 1935
as Flash
Crack-Up 1934
The Flaming Signal 1933
Honeymoon 1928
Shadows of the Night 1928
Under the Black Eagle 1928
as The Dog
His Master's Voice 1925
as Flash, Son of Thunder
Credits from TMDB.