A while back I posted that a lady who has two dogs from me (and two others) had a friend who lost her puppy from HGE. In a matter of two days. Well my friends dog Jackson got bloody poop yesterday out of nowhere and she rushed him to the emerg. room. He has it. He is a teapot, much bigger than the small 3 lb puppy who died, but they diagnosed him and treated him and now he is home.
So scary....here is a link to learn about this disease
Veterinary Q & A - Hemorrhagic GastroEnteritis (HGE) in Dogs