Friend, a dog being in heat should not cause her to have the symptoms that you are describing of vomiting, lethargy, bloody diarrhea, etc. In a puppy, these symptoms are likely related to dietary indiscretion, intestinal parasites, ingestion of a foreign body, infections (parvo), etc. to name a few causes. To determine the exact underlying cause she will need to be seen by your veterinarian for a hands-on examination, fecal analysis, x-rays and blood work as an initial screening test. Strongly recommend having her checked as soon as you can; it is important to rule out parvo virus. In the meantime, in any case of vomiting and diarrhea, the first thing to do is give the gastrointestinal tract 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) 0.1-0.2mg per pound body weight every 12 hours. 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.
3- After 6-8 hours offer a small amount of water. Wait half hour, if no vomiting, 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 concerned I would look into your local ASPCA or Shelter where they often offer veterinary services at a lower cost.
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