That's one nasty looking bite. I would see a Doc or go in to the ER. May need stitches or at least some antibiotics. You do not want to take a chance with loosing a finger over this. I work in a hospital X-ray dept with supports the ER and see lots of instances of people coming in well after the fact because they thought it was nothing. Had they been timely with seeking treatment, serious complications would have been avoided. BTY, Dog bites are usually cleaner than the human variety. Think it has something to do with the amount of saliva! Cat bites are the worst.
John