I would be honest and ask if they are prepared to lock the dog into a bedroom during the do, because after your husband was bitten that is the only way you will visit their house again.
If it offends them, so what? Your husband is the injured party here, not the neighbours or their dog.
If you want to be less forthright than I would be, some will call it rude, go with Ohmother's or Urmstronggran's suggestion.
If you don't tackle the issue now, you never will be able to visit and what will you say to the next invitation?
COUNTRY, CITY, AREA, PLACE -Game 21