Hi peacebabe :)
What breed of dog do you have?
I give 50mg bcomplex and with the digestive enzymes i give the normal human grade ones you can buy at the health shop,here is what the enzymes contain,so you know what to look out for:protease....lipase....alpha amylase..cellulase...lactase...papain. They each help digest different foods. protease/protein. lipase/fats amylase/carbs.
I give both of them(1 of each) straight after my dogs have eaten. It is not advised to give b vitamins on an empty stomach as it can cause nausea!
There is this one particular spot on our walks where the pigeons would roost,there was piles of poop underneath them,about 100 metres before we reached the spot my dogs used to take off and scarf down as much as they could before i got there! There was also duck poop and the odd cat turd

Anyway 3 days after i started giving the b and enzymes we went back to the pigeon walk and they completely ignored the poop,i was utterly amazed,i didnt think it was going to work that quickly and easily :D They havnt touched poop since,this was around 6mths. ago. The only other thing i've added is wheatgrass,i grow it myself in a little pot and the dogs can graze on it whenever they want.
Hope i've helped a little,anything else you need to know,just ask :)