Page in support of dog show (4)
I believe the answer is:
pomp
'show' is the definition.
(thesaurus)
'page in support of dog' is the wordplay.
'page' becomes 'p'.
'in support of' is a charade indicator (letters next to each other) (I've seen this in other clues).
'dog' becomes 'pom' (I've seen this before).
'p' put after 'pom' is 'POMP'.
(Other definitions for pomp that I've seen before include "Ceremonial display" , "Ceremony or ostentation" , "Splendid ceremonial" , "Ostentatious ceremony" , "Excessive ceremony" .)