My dog ate breakfast, vomited it, had 1 normal stool and then had 2 episodes of pooping blood. He did not eat dinner.

I'm sorry to hear about this with Boots.

You appear to be describing hematochezia - frank, nondigested, blood in the stool indicating bleeding from the lower gastrointestinal (GI) tract, such as the colon, rectum, anus, or anal sacs.

It can due to disease of the distal GI tract or, less commonly, hemostatic/clotting disorders. The GI disease may be primary (neoplasia - benign polyp or malignant cancer; colitis) or secondary (e.g., uremia from kidney failure; hypoadrenocorticism/Addison's disease).

GI diseases predominate and include infectious organisms - parasites, bacteria, fungi; acute hemorrhagic diarrhea syndrome, inflammatory bowel disease, pancreatitis, drug administration, and many types of colitis.

Boots' vet will need to consider all of the above.  To know if he's an emergent patient, please check his vital signs for me...

1) Check his gum and tongue color. They should be nicely pink - not whitish (anemia) or bluish/greyish (cyanosis/hypoxia/lack of oxygen to his tissues).

2) Check his respiratory rate at rest. He should be taking less than 30 breaths/minute while asleep or at rest.

3) Take his rectal temperature. Any body thermometer will do when placed 1.5" into his rectum for 1 minute. Normal is 100.5-102.5F (38-39.2C). This is a two person job!

Please let me know what you find.

Thank you.  Because he's not emergent an ER visit isn't needed at this time but I do want you to continue monitoring those vital signs as there are diseases that can rapidly result in profound anemia.  Do have Boots' vet attend to him tomorrow.  Please respond with additional questions and concerns if you wish.

You're quite welcome.  If you need clarification on anything I've posted or have additional questions or concerns, please don't hesitate to ask.

It's my pleasure.