Here are some possibilities, but only a vet can diagnose the cause:
* Anal gland issues: Dogs have anal glands that release a smelly liquid when they defecate. These glands can become impacted or infected, leading to bleeding.
* Parasites: Internal or external parasites like worms or fleas can cause irritation and bleeding in the anal area.
* Trauma: Injuries from accidents, fights, or rough play can cause cuts and bleeding.
* Tumors: Some tumors can develop in the anal area, leading to bleeding.
* Other health issues: Proctitis (inflammation of the rectum), colitis (inflammation of the colon), and other conditions can also cause bleeding.
Please don't wait to seek professional help. Your dog's health is important!