Not school related, i need on finding a dog food. i have 2 chihuahuas and ones getting older, she's having problems with her back and joints it seems. weve been feeding them rachel ray and they did fine& we've always fed them purina, no problems. i would like one that isn't too expensive. they don't really eat a lot they're only.5& 8 pounds appx. can anyone ? ive noticed that recently they don't like the purina dog food & we feed them the soft kind to with digestive .