This will probably sound kinda silly, but what did you do to teach the dog/cat to stay out of or away from the baby's things? The same approach worked for both our cats & son! LOL
We just kept redirecting. They could examine each others' things, but we were very clear that this is the kitties' and this is the baby's (we didn't have dogs until my son was 2). I think it's a curiousity phase for both when they find something new.
If our son was playing in the food, we gave him his own food, like cheerios or something so it was a similar size/texture but safe for him to eat. If he was playing in the water, we gave him some water in a bowl in the bath he could play in without making a huge mess all over the floor. Again- that's theirs, this is yours.
It took a couple of weeks of consistent redirecting, but after that it wasn't a problem. By the time my son was born, the cats knew they were no longer allowed in the baby's room unless we were with them. At 3, my son started volunteering to feed the cats, and has recently (at 4.5) started feeding the dogs too. He'll be the first to get on to any of the pets for messing with something that's his, and he'll give them their toy instead.
My brothers also had a tendency to eat the dog/cat food when they were young (up until 5 or 6, when they'd start daring each other to eat it!). If it makes you feel any better, they never got sick. It just grossed out my sis & me, so I think at that point it was more about the shock factor/reaction.