Form of art devoured by spry elderly setter? (5,4)
I believe the answer is:
still life
'form of art' is the definition.
(type of picture)
I can't explain the rest of the clue.
(Other definitions for still life that I've seen before include "Painting of inanimate things like fruit or flowers" , "Painting of inanimate objects like fruit and flowers" , "Painting of flowers, fruit, etc" , "rt-form" , "Painting of a bowl of fruit, perhaps?" .)