Hi penny82,
Here's what I would do in your circumstance:
1) Get the pup to a vet if its an open wound. It does not have to be much before infection sets in. Follow advise of vet.
2) Try not to separate the pup from its litter. It is especially critical for pups below 2 months / 8 weeks not to be separated from the litter. Why? Because, in essence, it will grow up to be a neurotic dog.
Before you separate young pup from litter, see this:
http://www.veterinarypartner.com/Con...&S=0&C=0&A=452
http://www.ccc.govt.nz/Animals/Criti...evelopment.asp
3) Once separated from litter, it's considered an orphan. So, to care for the orphaned pup, try doing the following as listed here:
http://www.veterinarypartner.com/Con...&S=0&C=0&A=576
I would think which milk brand is the least of your worries if you separate pup from the mother.
All the best