I am sorry that you are having this problem with Molly. As you may already know vomiting and diarrhea can be caused by many different medical conditions. It will be difficult for me to determine the exact underlying cause without a hands-on examination and some testing, I am sorry. But, in a young dog like Molly common causes are dietary indiscretion, intestinal parasites, ingestion of a foreign body, infections, etc. to name a few causes.
I am going to make some recommendations that you can try at home if she continues to vomit the next step would be a hands-on examination with your family veterinarian and x-rays as an initial screening test. In any case of vomiting the first thing to do is give the stomach time to rest. This is what you can do:
1- Do not give things like Pepto Bismol or Imodium. Start her on Pepcid AC (famotidine) 10mg 3/4 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 6-8 hours. Need to give her gastrointestinal tract time to rest. Keep her in a cool room and no exercise when fasting.
3- After 6-8 hours offer a small amount of water. Wait half hour, if no vomiting she can continue to have water but hold on the food for 12-16 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- If she continues to vomit after doing the above she will need to be seen by your family veterinarian for a hands on examination and x-rays as an initial screening test.
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