Asset with mice all over the place, bring in a feline (7,3)
I believe the answer is:
siamese cat
'feline' is the definition.
(I know that Siamese cat is a type of house cat)
'asset with mice all over the place bring in a' is the wordplay.
'with' is a charade indicator (letters next to each other).
'all over the place' is an anagram indicator.
'bring in' means one lot of letters goes inside another.
'asset' after 'mice' is 'miceasset'.
'miceasset' with letters rearranged gives 'siamesect'.
'siamesect' going around 'a' is 'SIAMESE CAT'.
(Other definitions for siamese cat that I've seen before include "Feline breed" , "Kitty" , "Carnivore" , "What might be cunning" , "Animal" .)