I am sorry for the delay in response I had some technical problems at this end. In response to your question, vomiting and diarrhea can be caused by many different medical conditions. Common causes are ingestion of a foreign body, infections, intestinal parasites, or even part of a systemic disease, etc. to name a few causes. If he is not getting better after fasting I would recommend a hands-on examination with a veterinarian for a fecal analysis, blood work, and x-rays as an initial screening test to determine the exact underlying cause. Treatment will be based on exam and test results. In the meantime, this is what you can do:
1- Do not give things like Pepto Bismol or Imodium. You can start him on Pepcid AC (famotidine) 10mg every 12 hours. You can buy Pepcid AC over the counter in any pharmacy.
2- No food or water for 3-4 hours, need to give his gastrointestinal tract time to rest. Then, offer a small amount of water followed by a diet of rice (75%) and boiled boneless chicken or ground beef (25%) until the stool is back to normal then wean him back into his regular diet.
3- Supplement with a probiotic, these are friendly bacterias that help with regularity. You can buy this over the counter in any pet store.
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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