Hi,
It really does seem to be affecting a heck of a wide set of animals to be IBD Tiff.
There are a few parasites that can cause the symptoms you mention (some protozoans and a couple of others I think).
This is why a lot of people wince when they hear of people taking in animals from rescue centers.
They are always short of cash and, typicaly (but not always ), have neither the manpower or resources to really deal with half the problems they get.
By their very nature they get a lot of the real problem cases - and those cost money at a heck of a rate.
At this point it's possible they are actually increasing the chances of the animals dying compared to the situation they were "rescued" from.
I hope they get some of the animals tested to find out what the problem is and manage to get it under control.
dr del