Why is my dog's skin red and itchy, and he has bloody diarrhea?
There are probably two separate issues going on with Buster.
His skin looks very irritated and infected which usually occurs because of an allergy or fleas. To treat this he will need to be put on a good flea control, antibiotics and something to help the inflammation in the skin.
Bloody diarrhea is usually indicative of colitis, gastroenteritis, or pancreatitis. I would be concerned also about intestinal parasites, Buster possibly getting into something he shouldn’t have, or less likely,irritable bowel disease.
Because Buster has several issues going on I would recommend taking him to a vet to be fully worked up. Your vet will likely want to run a fecal test, a skin scrapping and cytology (to understand the cause of the skin infection) and possibly blood work and X-rays.
I hope this helps. Best of luck. Thanks for using Petco Pet Education Center, formerly Petcoach.
Updated on September 23rd, 2025