But a 5 week old puppy is too young to be away from its mom in any case. The longer a puppy stays with its mother (until at least 8 weeks) the better chance it will have learned to socialize, inhibit its bite, and other skills it needs to learn.
Please think two and three times about this before you start. There are many dogs that are safe with ducklings, but often they are well-trained adults that the owner knows is gentle with other animals.
Some dogs are very gentle. Others have a huge prey drive. You need to know the breed of dog...