Gun dog with no tail gets to fetch (8)
I believe the answer is:
retrieve
'to fetch' is the definition.
(retrieving is a kind of fetching)
'gun dog with no tail' is the wordplay.
'gun dog' becomes 'retriever' (retriever is a kind of gun dog).
'with no tail' means to remove the last letter.
'retriever' with its final letter taken away is 'RETRIEVE'.
'gets' acts as a link.
(Other definitions for retrieve that I've seen before include "Rescue" , "Go for and bring back" , "Win back" , "Get or bring back something" , "Revere it to get back" .)