I don't think Pet Talk is going down hill. Does it need help? Maybe.

As a former admin of a BBS, my suggestions would include:

Delete zero-post members every 60 days
Hire more mods and admins to help take care of this place. It's enormous!
Delete same subject threads. If the board gets too cluttered, it's not fun to navigate around. Also, move topics that don't get posted in their appropriate forums.
Keep members from regestering if their IP address matches that of another member. (Members can only register one user name)
Be a little more strict with the rules. (although it's not too important around here)

Just some ideas. I think Pet Talk will be around for a long time to come.