Wash the bite with soap and lots of running water for several minutes first; dog-mouth bacteria in a puncture wound are the main threat.
Then get assessed today if: you have not had a tetanus vaccine in the last 10 years, the bite is on hands, feet, face, or head, the dog was a stray or unvaccinated, or you were bitten abroad, because tetanus boosters, antibiotics, and rabies prevention are all time-sensitive and the NHS checks all three. Redness, swelling, pus, or worsening pain are infection signs needing prompt care, and deep wounds or heavy bleeding are the ER territory.
What to do
Common questions
My dog bit me - do I need a shot?
Maybe, and the assessment is quick, so do not sit on it. First aid: wash the wound with soap and lots of running water for several minutes, because dog mouths carry bacteria and punctures drive them deep. Then the shot question has two parts. Tetanus: the NHS lists not having had a tetanus vaccine in the last 10 years as a reason to get medical help for a bite, and a booster is routine for dirty wounds when your last dose is old. Rabies: risk depends on the animal and the country; a vaccinated pet dog in the UK or US is essentially zero-risk, while a stray or unvaccinated dog, or any dog bite abroad in a rabies country, is an urgent assessment, and the NHS notes you will be checked for tetanus and rabies risk and given preventive treatment if needed. The see-someone-today triggers from the NHS: the bite is on your hands, feet, face, or head; the bite was by a person; it has been 10 years since your tetanus vaccine; or there are signs of infection like redness, swelling, pus, or worsening pain. the ER is for deep wounds and heavy bleeding.