Good Morning and welcome! I am Dr. Loretta, a licensed veterinarian and I am happy to answer your question.
Most likely Millie has a mild dogestive disturbance that is causing this blood. It is not serious since the stool irritates the very sensitive rectal mucosa which causes the small blood vessels to break and bleed. Once the stool is normal, this will resolve on its own.
I would watch Millie for a day or so to make sure she is eating well and if this is minor, this will resolve on its own. Of course, if this does not resolve, have your vet examine Millie to be sure we have not missed something.
Does that make sense to you?
Please let me know if you have ANY other questions. My goal is to give you 100% satisfaction and if you are not yet satisfied, please REPLY so I can clarify for you.
Sincerely, XXXXX XXXXX
Thank you so much, Elizabeth, for your kind rating. It is very much appreciated! Even though you have rated, we can still communicate. If you have other questions, please Reply. I am always happy to help. I am sure Millie will do well with your love and care.
Have a wonderful day!