Too be more objective...

That's what it smells like to my sensitive nose..

Though it may not have actually been caused by a malevolent cat.
Seems from google research,
guitar cases closed up for too long can incubate moulds
that end up stinking as bad as foulest feline fluids.

Luckily the good quality Korean Les Paul copy I rescued from the case
aint in such bad shape
and wiped down quite nicely with Tesco 'all surfaces' anti bacterial kitchen cleaner.