When can a 5 week old puppy take a bath?

The mother dog keeps the puppies clean until they are around 6 - 8 weeks old. After that time, she has already begun weaning them, and is not cleaning them as she did when they were newborns.

So from 6 - 8 weeks is when it's saft to bathe a puppy, but be sure to use a shampoo made especially for puppies. Never, ever use a shampoo for people, and if you need one for flea control, make sure the label says it's safe for puppies.