It looks very authentic and old to me. Good find. Although there are a lot of fake Chinese antiques out there, this one does not look like one. The wear, the damage, faded paint all look good. Even with the damage I think your foo dog is terrific. It is really hard to put a value on something like this, because although genuine wooden foo dogs can be highly sought after, you have only one of the pair and only the head, plus it is damaged. However, this one is still quite charming and attractive just as it is and I could easily see a couple of people getting into a bidding war over it. It is also possible that your foo never had a body, that he/she was an architectural feature. They are always in pairs though, one male and one female. If you got it at a flea market, I bet you got a good deal.