[mscat]

I had the same problem with my shih tzu. She is smaller then our yorkie. And I thought she needed to gain weight. I did not like feeling her spine and ribs so easily. Choose a high quality kibble, I chose Evo red meat small bites and mixed it in with their regular food. it did not take long for Suzi our yorkie to eat more then she should> It helped out shih tzu though and it toook a month , then I stopped the EVO . EVO is pricey but loaded with protein. Anther really good food is the Wellness Organic, canned food. That is high protein too, and is pricey. But worth it. When you feed canned you have more control over how much to feed then if you are only feeding kibble .
Our shih tzu looks better now, and Suzi well, I do think she gained a pound herself . She was 7 pounds last time she was at the vet, but even when we pick her up we can tell the difference. I am actually glad that Suzi is not a picky eater, but, she does not need to gain anymore weight.