Following up on the link FarNorth gives. I think the problem is clear. Your DiL does not want her children going to a house where there are dogs. It is the dogs that are the problem and the evidence that they live in your house, even when they are elsewhere; smell, fur, the danger, hygiene are all things that can worry someone who doesn't like dogs. Your grandchildren may have asthma or allergies or be frightened of dogs. You do not say what kind of dogs you have or how many
I think you need to accept that just as you love dogs, especially your own, other people really do not like dogs and do not want to be anywhere they are or where they live. Both views are equally valid.
You talk about your DiL being cold, do you not think that you too are being unreasonable?