Dog tails are docked at days 2-3 after birth before the nerves are fully knit to the brain to minimize any possibility of pain or discomfort.
If they are docked after the age of 5 days then it requires anesthesia and needs to be done by a veterinarian.
Typically the tail is docked to leave 3-4 vertebra rather than a inch designation.
With a 7 week old pup it would be likely best to wait to 12 weeks or when ears are done to consider tail docking during the same anesthesia use.
Hope this helps you!
Those people forgot to tell you that the procedure of banding is done at a couple days old not seven weeks.
No you cannot dock at home at this age.
The time for banding as a docking method is at 1-3 days of age. Tyipcally to do it correctly even then you need a mentor well trained in doing it correctly so you do not end up with a gangrene infection that kills the puppy.
Surgical docking in pups is normally done at 2-3 days of age though some vets insist on 5 days which in my experience puts the pups in pain.
Thank you very helpful