My son was just bitten by a dog. showing 2 small cuts. do we need to take him for tetanus injection now after hours, if at all? otherwise, is it ok to wait until normal office hours tomorrow?

Tomorrow is OK: Dog bites have a high chance of getting infected. Rabies is rare. Make sure you wash the area thoroughly with an iodine based solution and apply a topical antibacterial ointment and cover with a bandage. Check it frequently. If the area becomes more red or the redness spreads outward, and becomes more painful or warm to the touch, see a doctor immediately for antibiotics/rabies injection.