I'mCustomerand I would be glad to help with your question. I'm sorry your dog Chile isn't feeling well. Stress, of which pain is one example, can result in diarrhea and loss of appetite. It would be uncommon, but still possible, for pain to cause vomiting. Because pain after spay surgery is not commonly associated with vomiting, I would recommend ruling out other causes of vomiting. Spay surgery complications should also be considered: such complications are infrequent but can be serious (i.e. damage to one or both ureters causing kidney pain/failure, post-surgical infection, etc.). Fecal exam to rule-out parasites, routine lab work to help look for metabolic disease, pancreatitis, etc. and possibly abdominal x-rays should be considered. It is possible all those tests would still not provide an explanation as to why Chile is vomiting and having diarrhea: perhaps she ate something we don't know about that upset her gastroinestinal tract.
If you prefer a more conservative route due to the expense of the diagnostic tests, then subcutaneous fluids to correct/prevent dehydration, an injection for nausea and opiod pain medication by injection (i.e. buprenorphine, hydromorphone) followed by Tramadol pain medication orally would be logical steps for the next 24 hours. I would not recommend use of non-steroidal antiinflammatory drugs such as Rimadyl (i.e. generic name carprofen) as they can contribute to GI upset. If there is no improvement after 24 hours of conservative therapy, then the diagnostics metioned above should definitely be performed.
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