Crazy pets made a sudden rush (8)
I believe the answer is:
stampede
'crazy pets made a sudden rush' is the definition.
(I've seen this before)
'crazy pets made' is the wordplay.
'crazy' indicates anagramming the letters.
'pets'+'made'='petsmade'
'petsmade' is an anagram of 'STAMPEDE'.
(Other definitions for stampede that I've seen before include "Deems apt to have flight of cattle" , "Headlong rush of animals" , "Wild run of frightened cattle" , "Pasted me (anag.)" , "Panicked rush (of cattle)" .)