Being adequate in feeding Fido, perhaps (5)
I believe the answer is:
doing
'being adequate in feeding fido perhaps' is the definition.
I can't judge whether this definition defines the answer.
'in feeding fido perhaps' is the wordplay.
'feeding' indicates putting letters inside.
'fido perhaps' becomes 'dog' (I can't justify this - if you can you should give a lot more credence to this answer).
'in' going inside 'dog' is 'DOING'.
Can you help me to learn more?
(Other definitions for doing that I've seen before include "Engaged in -- active" , "Beating (colloquial); performing" , "Making" , "Accomplishing" , "Performing a task" .)