Why does my dog have bloody stool?

If this is a recent, isolated occurrence, you shouldn't panic quite yet. Blood in your dog's stool is either referred to as hematochezia or melena, depending on which part of the digestive system the blood is coming from (upper or lower). With hematochezia, the blood is bright red and looks fresh, meaning it came from the lower digestive tract close to the colon or the anus. A few causes of hematochezia are: parvovirus, dietary sensitivities, internal injury, or parasites (hookworms, roundworms, etc.). In each of the above cases, you should visit your veterinarian if you notice the blood is still present in the stool after a day. With melena, the stool will appear black like tar, meaning that the blood is old and has gone through the digestive tract, therefore originating from the upper digestive tract. Some potential causes of melena are: use of pain medications, post-surgery complications, ingestion of blood, trauma, intestinal blockages, tumors, and bacterial infections. Again, if you notice this symptom for longer than one day, it is best to seek your veterinarian's advice immediately. What I have stated above are just a few possibilities and are not diagnostic by any means, for each individual situation is different.

Here is a great website for more in-depth information and images regarding bloody stool identification:

https://pethelpful.com/dogs/Causes-of-blood-in-a-dogs-stool (https://pethelpful.com/dogs/Causes-of...)

If it's a lot you n Ed to get them to the vet asap. If it's just a little bit it could be from straining while going to the bathroom. Keep an eye on them and anything more get them to the vet

It's important to distinguish between fresh (bright red indicating the source is lower intestines/anus/rectum) blood or dried (darker-even tarry or black- where blood is maybe coming from the upper intestinal tract and is more worrisome than the other) blood in the stool. The reasons can range from a dietary change to a serious disease. Other possibilities include an infection (bacterial, virus, fungal, parasites), an intestinal obstruction/blockage, ulcer, abdominal issues, food-borne illness, allergens and stress. If you see the dog's activity level is lethargic, is vomiting, has fever, dark-colored or bloody stools, straining to defecate, decreased appetite or unexplained weight loss, please contact your vet for a visit.

Definitely take him or her to a vet. If the blood is coming out while pooping, from my experience, it can be worms (parasites). Either way, treatment is needed.