Our daschound had a litter of 3, now they are 7 weeks old. 2 of them seem to have a neck problem. Most of the time they hold their head crooked, but then sometimes it appears to be no problem. Does anyone have any idea what this could be and anything to do for it?

I'd get it checked out by your vet. Dachshunds are known to have back and musculoskeletal problems because they were bred to be long and short. It could be a genetic problem that I'd get an expert to look at asap. Be prepared to pay for some x rays.

Why haven't they been to the vet yet? Where both parents checked and cleared of any health problems before you choose to breed them? I am very concerned with the number of uninformed breeders visiting this site recently. I hope that you will choose to fix your dog to prevent anymore pregnancies, especially if you have already bred puppies with health problems. PLEASE take the puppies to the vet ASAP. If you are unable to care for their medical needs, please contact a rescue so they can.