I just want to say how terrible for the pets and their owners that this happened, but it is something we humans should watch out for too, as they say this is likely what affected those who were subsequently persecuted and put to death as witches in Salem, Massachusettes during the witch trials. I have read that there was probably a bad batch of aspergillis fungus that made the people act nutso, and they paid with their lives too.
As for whether or not there are non-corn based foods for our pets,we use Nutro Nuggets that we get either at Petsmart or at our local feed store, it has meat(lamb, beef or chicken) as the #1 ingredient, and they have both cat and dog dry food. We have three couch critters that love the Natural Choice variety. Our one cat, the supreme ruler of all animals within our home, will not eat anything other than Whiskas, so I let her have her way. Nutro is a little more expensive, but more than makes up for that in that the dogs have firmer waste products that are less frequent than with other foods(to put it in the most acceptable words), and really seem to get more nutritional value from it, as we have them(A red heeler, a pomchihuahua, and a terripoo) on free choice and they eat approximately a cup and a half between them daily. I would say they are really happy with it as they get no otherfood from the table scraps or anything.