Like Pavlov's dogs in servitude (7)
I believe the answer is:
slavery
'servitude' is the definition.
(thesaurus)
'like pavlov's dogs' is the wordplay.
I cannot really understand how this works, but
'like' could be 'y' (similar in meaning) and 'y' is located in the answer.
The remaining letters 'slaver' is a valid word which might be clued in a way I don't see.
This may be the basis of clue (or it may be nonsense).
'in' acts as a link.
(Other definitions for slavery that I've seen before include "Extreme drudgery" , "State of subjugation" , "Bondage" .)