Can anyone suggest how to make an icing/frosting to decorate dog treats with that doesn't use confectioners sugar, but would still harden like royal icing? I purchased some icing that you just add water to that works real well, but could prove to be costly for decorating a lot of treats. The icing I purchased was yogurt-based, but most of the yogurt-based recipes I have found say the icing doesn't harden.
So... I did a little research. There exists in the world a substitute for chocolate that is doggie safe: carob. This is much less sweet and lacks the toxic substance (theobromine) that makes chocolate dangerous to dogs. Even white chocolate has this issue, though much less so. and suffers from sugar volume.
Basically, take 3 cups of white carob chips and melt. Add 1 tsp of vegetable oil and some desired food coloring and mix thoroughly. Dip, spread, or pipe the icing onto the treats and allow to cool. The carob should harden again when it cools.
You should be able to find these chips at health food stores or, perhaps, online if necessary.