Animal caught in field eaten by kitty (7)
I believe the answer is:
polecat
'animal' is the definition.
(I've seen this before)
'caught in field eaten by kitty' is the wordplay.
'caught' becomes 'c' (cricket abbreviation).
'in' is an insertion indicator.
'field' becomes 'lea' (lea can mean a meadow or field of grass).
'eaten by' is an insertion indicator (inserted letters get eaten).
'kitty' becomes 'pot' (both can mean a shared fund).
'c' put within 'lea' is 'leca'.
'leca' placed into 'pot' is 'POLECAT'.
(Other definitions for polecat that I've seen before include "weaselly type" , "Weasel-like creature" , "American skunk" , "Malodorous carnivore" , "Smelly American mammal" .)