Very bad manners. Iam is a dog lover - her guests knew that, but still realised that there were some house rules to abide by with little ones there (and even without).
Your guests Tutumuch were extraordinarily rude and selfish. I have been in your position, with no children here, and have said very clearly that it is our choice not to have dogs in our home or garden: smell, hair, slobber, shit in the garden, boisterousness etc. - our home, our garden, our rules. Enter blackmail stage left!......but she will get too hot in the car etc. I know she will, so why bring her in the first place, when you know how we feel?
OH is frail and ill - do I want a dog knocking him over? - no I do not.
I respect that others enjoy their dogs - that is fine - but I do expect them to get their heads round the fact that not everyone shares that view and to act accordingly. It is not difficult!
You have all my sympathy. Don't invite them again!!