Domestic animals pace backwards (4)
I believe the answer is:
pets
'domestic animals' is the definition.
(animals in the home)
'pace backwards' is the wordplay.
'pace' becomes 'step' (synonyms).
'backwards' is a reversal indicator.
'step' reversed gives 'PETS'.
(Other definitions for pets that I've seen before include "Domesticated animals" , "Animals at home" , "Little darlings - step on them" , "Domestic animals" .)