Just read the composition of the skinners dog foods, i wouldn't feed it to a gerbil , not that i would feed dry food anyways but it is so far from a dogs nutritional needs it is scarey. Here is the chicken and rice composition as an example, the first two ingredients say it all really!
Maize, chicken meat meal (17.5% min), whole rice (15% min), oats, chicken fat, white fish meal, vitamins, minerals and trace elements, brewer’s yeast, culinary herb mix.