Dog food (4)
I believe the answer is:
chow
I believe this clue is a double definition.
'dog' is the first definition.
(short for chow chow)
'food?' is the second definition.
(chow can informally mean food)
(Other definitions for chow that I've seen before include "Nosh" , "Grub" , "Dog (from China?)" , "Long-haired dog of Chinese breed, or informal food" , "breakfast?" .)