Nosy Catalan's casually abandoning pet (5)
I believe the answer is:
'nosy' is the definition.
(relating to the nose)
I don't understand the remainder of the clue.
(Other definitions for nasal that I've seen before include "Describing some hooter" , "Relating to one's hooter" , "Like some spray" , "front piece of helmet" , "pinched" .)