Friend, if your dog did not eat feces I can assure you that he did not vomit poop. You see, once the food is in the colon (large intestines) as feces it will not travel back up to be vomited. The feces like odor is likely the stomach content had been there for a while and for this reason acquired that odor, this is common. The big question is: Why is he vomiting? Vomiting 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. But, common causes are: A simple gastritis, dietary indiscretion, intestinal parasites, ingestion of a foreign body, infections, etc. to name a few causes.
I would recommend you keep an eye on him, if he continues to vomit this is what can do:
1- Do not give things like Pepto Bismol or imodium. Start him on Pepcid AC (famotidine) 10mg 1/4 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 his gastrointestinal tract time to rest. Keep him indoors in a cool room when fasting.
3- After 6-8 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.
4- If he continues to vomit after doing the above he will need to be seen by your family veterinarian for a hands on examination.
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