Exhausted corgi carried by son/heir (5)
I believe the answer is:
scion
'sonheir' is the definition.
I can't judge whether this defines the answer.
'exhausted corgi carried by' is the wordplay.
'exhausted' suggests removing the centre (the word is emptied out or exhausted).
'carried' is an insertion indicator (one word carried by another word).
'by' becomes 'son' (I can't justify this - if you can you should believe this answer much more).
'corgi' with its centre taken out is 'ci'.
'ci' put inside 'son' is 'SCION'.
Can you help me to learn more?
(Other definitions for scion that I've seen before include "Descendent - heir" , "Offshoot" , "Young shoot/twig" , "Younger member of a family" , "Young family member" .)