Hi Maria,

I just happened to Google that this morning! I ordered some Bio-Sponge for a 31 yr. old gelding (nonIR, nonPPID) with loose manure,  and the only ingredient listed on the container is di-tri-smectite. What I learned, in a nutshell, is that smectite is a type of clay  with viral and bacterial absorbing properties, also used to treat acute diarrhea in children. Bentonite clay might contain an amount of smectite, but apparently the amount is variable. I’m sure there will be others who will chime in with more information and, hopefully, who will share their Bio-Sponge experiences. 

Carla