Old things are dried up.  Lack of water.
Ageing. See it everywhere.

Dried up old trees, wood, plants, fruits, vegetables
begin to rot and die.

Dried up people and animals have
wrinkling, withering, dry, old, crusty sagging skin.

The guts, the insides must match that condition
and dry up from the inside out.

Unable to keep  and transfer the proper amount
of water flowing in the system
the living organism ages, degenerates and dies.