Unskilled in pet management (5)
I believe the answer is:
inept
'unskilled' is the definition.
(thesaurus)
'in pet management' is the wordplay.
'management' indicates an anagram.
'pet' is an anagram of 'ept'.
'in'+'ept'='INEPT'
(Other definitions for inept that I've seen before include "Not competent" , "pointless" , "Clumsy and incompetent" , "Lousy" , "Incompetent or awkward" .)