Why do dogs have blood in their stools?

When blood in the stool is evident in dogs, it is often indicative of some intestinal mucosal ulceration or bleeding. If the bleeding is a dark brown, tarry clot or a bleeding stool, it is likely to be in the small intestine and is most likely caused by intestinal parasites such as coccidia. If the bleeding is in the form of bright red blood clots accompanied by jelly-like material, this is likely to indicate an ulcer in the intestinal mucosa, usually due to acute gastroenteritis or viral gastroenteritis. If there are blood droplets or blood droplets at the end of the stool, the bleeding is probably in the large intestine and may be caused by colitis or colonic mucosal ulcers. If you find blood in the stool, you need to go to the vet for a diagnosis and treatment.