Friend, I am sorry your dog is vomiting and has diarrhea. In response to your question, it is possible that the vomiting and diarrhea are caused by the ingestion of part of the mouse. Or, there could be something completely different like an infection, ingestion of a foreign body, or even part of a systemic disease, etc. to name a few causes. Unfortunately, on history only it will not be possible to determine the exact underlying cause, I am sorry. The fact that this has been ongoing for 2 days I am a bit concern about her hydration. I would strongly recommend a hands-on examination with your family veterinarian in the morning to determine the exact underlying cause. In addition, she may need supportive care. In the meantime, this is what you can do:
1- Do not give things like Pepto Bismol or Imodium. Start her on Pepcid AC (famotidine) 20mg tablet every 12 hours for the next 2-3 days. You can buy Pepcid AC over the counter in any pharmacy.
2- No food or water for 4-6 hours. Need to give her gastrointestinal tract time to rest.
3- After 4-6 hours offer a small amount of water. Wait half hour, if no vomiting, continue to give her water every hour or so. Leave her without food for 8-12 hours then offer a small amount of rice (50%) and boiled boneless chicken or ground beef (50%) 4-6 times a day. Keep on this diet for several days then wean into regular diet.
4- Follow up with your family veterinarian for a hands on examination. If cost is a concern look into your local ASPCA or Shelter where they often offer veterinary services at a lower cost.
5- If at any point she become lethargic, abdominal swelling, pale gums, etc. have her checked by nearest ER veterinariaan.
My goal is to provide you with excellent service - I hope I've provided the information you were seeking, if you feel you have received anything less, please reply back as I am happy to address follow-up questions. Kindly rate me when you are done.