Talking about things that can harm your dogs, here is some more information.
Raisins or Grapes
Anti Freeze (and other products you may use to de-ice in winter that contain anti freeze)
Plants on the attached link http://www.dogpack.com/health/poisonplants.htm
Too much Asprin & Asprin subsitutes (Tylenol) are always toxic http://www.school-for-champions.com/animalhealth/aspirin.htm
Below are some helpful links regarding this:
Poison Help Site
Even More Toxins