Friend, when we see vomiting of undigested food it is called "regurgitation" as the food has not been digested. Possible causes could be esophagus disorders (megaesophagus, strictures, parasites), gastritis, ingestion of a foreign body, etc. to name a few causes.
I am going to make some recommendations below, if she continues to regurgitate the next step would be a hands on examination with family veterinarian and xrays as initial screening test. This is what you can try:
1- Do not give things like Pepto Bismol or imodium. Start her on Pepcid AC (famotidine) 10mg 1/2 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 8-12 hours. Need to give her gastrointestinal tract time to rest.
3- After 8-12 hours offer a small amount of water. Wait half hour, if no vomiting, offer 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.
Note: If possible place her eating and drinking bowl on top of a small stool to force her to raise her head when eating.
4- If she continues to regurgitate after doing the above she will need to be seen by your family veterinarian for a hands on examination and xrays as initial screening test.
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