Soft food and hard exercise for a dog (4)
I believe the answer is:
mush
'soft food' is the definition.
(I've seen this before)
'hard exercise for a dog' is the wordplay.
I cannot really see how this works, but
'hard' could be 'h' (abbreviation used in pencil classifications) and 'h' is found in the answer.
The remaining letters 'mus' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
'and' is the link.
Can you help me to learn more?
(Other definitions for mush that I've seen before include "Face" , "Cloying sentimentality" , "Soft pulp or feeble sentimentality" , "order for dogs" , "Go on, Husky!" .)