What breed are the puppies?
Certain breeds are prone to heredetary lymphedema but again, it's one of those things that any breed can get even though certain breeds have a predisposition to it. The most common symptom is swelling that begins at the paws and progresses up the legs. It most commonly affects the hind legs but can affect all four legs and even progress into the underside of the chest, abdomen and even the tail. It doesn't usually cause discomfort but it isn't something that should be ignored.
The treatment for it is to deal with the symptoms and try to minimize them. Warm water soaks and massage and pressure wraps can help. There is a type of drug called a benzopyrone that can possibly reduce the swelling and give antibiotics for any secondary infections that might develop.
You need to get them to a vet to be examined because if this is what it is, you need to try to get it resolved or at least treat the symptoms. If it is severe, the puppies can die. It's important that you do whatever your vet tells you to do because every step of the maintenance is important if the puppies are to overcome this. I would get them into the vet first thing Monday morning unless you have an emergency vet that you can take them to this weekend. Depending on the severity of the swelling I might not advise waiting until Monday. Please let us know what the vet says.
Ghilly
My First thought is a "Heart Defect" in both puppies.....Thus, the swelling of the legs & feet.......I may be way off, but that's what comes to mind.....
You need to have your Vet take a look at this to determine what's happening.... As with any defect, you wouldn't want to pass these guys on to unsuspecting new owners.....
Have them checked out and let us know what you find out....Good luck....Karla