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One reason french fries can be so bad for Yorkies, is that fat in table scraps, can cause Pancreatitis. Yorkies get get this easily, for some reason. You can give your furbaby all kinds of healthy dog treats, as other members have mentioned. They can also have things such as green beans (with no salt and no meat) and apples, in moderation.
This is a great place to get all kinds of information. Hope you enjoy your first year with Muffin.