It sounds like they're sharing the same intestinal infection. You might want to offer just homemade (boiled) chicken and rice (no bones of course) to them for the next 24 hours.
http://placervillevet.com/canine%20gastroenteritis.htm
You can also offer, if necessary, Pepto-Bismol (1/2 tablespoon per 15 lbs, once a day) or Imodium A-D (1 teaspoon per 15 lbs).
Look here for more details about treating http://placervillevet.com/canine%20gastroenteritis.htm
It's very important to not go over the recommended doses and to be honest, I'd try all the 'diet' approaches first .
It seems you're quite concerned, which is a good thing. It shows that you're very involved in your dogs' lives, attentive and caring. Since both dogs are showing symptoms, it greatly reduces the possibility of it being a more serious disease and makes it more likely just a passing thing that should resolve in a day or two.
Let me know how it goes ok?
Many have forgotten this truth, but you must not forget it.
You remain responsible, forever, for what you have tamed.