Rarely dogs can get very sick from raw.
This is usually only a concern in dogs with a compromised immune system.
It is probably less likely with Nature's Variety because it has been frozen.
I think that any Yorkie who eats raw should be bile acids tested first.
"In my opinion", while raw is a more species specific diet, homecooked is safer. Lots of Yorkies seem to do very well on NV though.