'They're divine' -- some obsessed dog-lovers reflected (9)
I believe the answer is:
goddesses
'they're divine' is the definition.
(goddesses are divine)
'some obsessed dog-lovers reflected' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'reflected' shows that the letters should be reversed in order.
'sesseddog' is hidden in the letters of 'obsessed dog lovers'.
'sesseddog' backwards is 'GODDESSES'.
(Other definitions for goddesses that I've seen before include "Female deities" , "Iris and Isis, for example" .)