Expert, nowadays, at pet management (5)
I believe the answer is:
adept
'expert' is the definition.
(synonyms)
'nowadays at pet management' is the wordplay.
'nowadays' becomes 'AD' (AD, Anno Domini, as opposed to BC, Before Christ).
'at' says to put letters next to each other.
'management' indicates an anagram.
'pet' anagrammed gives 'ept'.
'ad'+'ept'='ADEPT'
(Other definitions for adept that I've seen before include "who gets the lapis philosophicus secret" , "One highly skilled could be taped" , "Handy" , "capable" , "Highly proficient" .)