Pets made mess in wild rush (8)
I believe the answer is:
stampede
'wild rush' is the definition.
(I've seen this before)
'pets made mess' is the wordplay.
'mess' indicates an anagram.
'pets'+'made'='petsmade'
'petsmade' anagrammed gives 'STAMPEDE'.
'in' is the link.
(Other definitions for stampede that I've seen before include "Panic-stricken charge of cattle" , "herd scatter wildly" , "Uncontrolled rush" , "Wild headlong rush" , "Flight of cattle in panic" .)