Dog can often retrieve game, injured initially (5)
I believe the answer is:
corgi
'dog' is the definition.
(corgi is a kind of dog)
'can often retrieve game injured initially' is the wordplay.
'initially' indicates taking the first letters.
The first letters of 'can often retrieve game injured' is 'CORGI'.
(Other definitions for corgi that I've seen before include "One of the Queen's dogs?" , "Welsh breen of dog" , "Toy car manufacturer" , "Dog popular with British royals" , "Dog at Buckingham Palace" .)