Advice please - I have a litter of 6week old pups at home and have a new pup from another litter/breeder due to arrive imminently. When I agreed to buy the new pup the breeder said she would keep for the overlapping 2 weeks but due to unforeseen circumstances is now unable to. The new pup has had the first jab and has come from a reputable breeder. Can I allow them all to interact? Any advice greatly received. Thank you.

The new bought in puppy may be part vaccinated but your own puppies are not.

Your puppies will of course have a certain amount of maternal immune protection but I would never consider introducing a strange puppy.
A puppy 2 weeks older could do a lot of unintentional damage to your litter!

Thank you very much indeed.

I'd add my advice NOT to mix this new puppy with your existing puppy, at least until your own puppies are old enough to have their first vaccination.   And even then I think I'd probably wait until those puppies you aren't keeping to go off to their new homes.It will probably be OK and better for the income puppy, but is it worth the risk?    It's a pity this other breeder can't stick with the original plan to hold the new puppy until your litter are that bit older.

Thank you. Your advice is much appreciated.

If I were buying a puppy I would be very uncomfortable that my puppy had been mixed with one from another litter.

I would also worry how mum would be atm given her pups are so young.  Isnt play in an older puppy potentially an issue too when they are so young ?
Is there no way the breeder can keep the pup a bit longer  as originally  arranged