A pig-foot horse (7)
I believe the answer is:
trotter
I believe this clue is a triple definition!
'a pig' is the first definition.
(thesaurus)
'foot' is the second definition.
(trotter is a kind of foot)
'horse' is the third definition.
(I know that trotter is a type of bangtail)
(Other definitions for trotter that I've seen before include "bit of a swine" , "Food for man" , "Pig's foot - type of racing horse" , "Pig's foot, or one on the run" , "bit of a pig" .)