The dog's digestive tract is quite short and this often means that it has trouble with the tough fibre in grains like wheat. (cuddleyourdogs.com)
However, oats processed in most factories are liable to be slightly contaminated by other gluten - containing grains like wheat and rye. (epicurious.com)
As well as lean meats, dried beans and soy foods, and whole grains like wheat germ. (fitbodyhq.com)