Slobbers/Dermatitis is when rabbit seems to be drooling and
the fur becomes matted and wet around the mouth and neck.
This is in most cases caused from an abscessed tooth.
If you find that the dewlap (Flabby part under your rabbits mouth and neck)
is what is wet and it remains wet, then there is possibility your rabbits has Dermatitis.
Observe your rabbits to see if the condition changes.
If you are sure it is Slobbers, you must see a vet to get
the tooth either clipped or surgically removed.

This problem is often found in older does with a large dewlap, that can drag on the cage,
floor and can hang into the water dish.
In this case, it is advisable to give her a water bottle instead, to prevent the dewlap from becoming
wet in water dishes.
Wet Dewlaps can get infested with maggots as well infection and death may occur.
The best thing is prevention.