The reasons why Teddy has blood in his stool:

1. Teddy is infected with parasites or parvovirus, and blood stains will appear in his stool.

2. When Teddy accidentally eats poisonous food and suffers from enteritis, he will also have blood in his stool.

3. It is also possible that Teddy has blood in his stool due to eating sharp food or scratching the intestines with bones.

Solutions to Teddy's bloody stool:

1. If serious acute hemorrhagic gastroenteritis is caused by accidentally eating toxic food, you should seek medical advice at this time. Seek medical attention promptly.

2. If the bloody stool is caused by simple gastroenteritis, it is recommended to use probiotics, pay attention to diet, and reduce inflammation.

3. If it is caused by parasites, Teddy should be dewormed in time.

4. If Teddy is infected with a virus, he should cooperate with a doctor for treatment in time.