Annie is really small and petite as well, and she had 6 puppies just fine... A couple of them were breech, but I only had to help her a little... She had 6 healthy beautiful puppies.

The only thing I would worry about is if a huge dog got her pregnant, then she might not be able to have them naturally..

The vet can do an x-ray to determine the size of the puppies heads, in relation to the size of her pelvis and see if she would be able to have them.

We had that done with the dog I fostered, because even though the woman she came from said she saw her breeding with a small male boston terrier, we weren't sure that was true and wanted to make sure that they were indeed small enough for her to have them. The shelter I fostered her for wanted to abort the puppies and she to was a week away from giving birth. So I took her in myself and paid to have her x-rayed to see if everything would go alright.

If it were me, that's what I would do... Because I'm thinking that if the puppies are only a week away from being born that they are almost fully formed puppies and they are indeed viable.. You can bring a pregnant dog in for an ultrasound and an x-ray as early as 25-26 days and they can see the heartbeats and can already see the skulls and spines of the puppies to count them.

Sorry this is so long... But I just don't think its right to spay her when shes this far along... Even though there are a lot of homeless dogs.