Apologies in advance for the long post. I will try to summarize, but want to provide complete information. Hopefully someone will know what's wrong with our little dog and what we can do for him.
Chase is almost 3, male, Yorkipoo, 12 pounds. Started vomiting bile 7 months ago (just bile, not food). He vomits 2-3 times in a row and then nothing until next incident. Typically happens overnight but sometimes during the day. Everything else is normal. Little sister Sophie eats/does same things with no issues.
September: Vet put him on Pepcid (an antacid), and then on Reglan (anti-vomiting med) but neither helped. Tried smaller meals more often but no results so back to feeding twice a day. Then started Cerenia (another anti-vomiting med), which works. Been on that ever since (except when we stop it to see if he's still vomiting). Since it only treats the symptom, we're trying to figure out the root cause of vomiting.
October: Vet did an endoscopy and saw excess bile and some inflammation. Biopsy showed abundant helicobacter organisms (which are normal but not that many) and inflammatory response (usually due to food allergies), but all white blood cells were normal. He prescribed Metronidazole and Amoxicillin (antibiotics), Pepto Bismol (antacid) while continuing Pepcid and Cerenia. Also tried Prednisone (steroid) for a week with no results.
November/December: Stopped all meds except Cerenia. Fed Chase nothing but Hills Science Diet z/d (hydrolyzed protein diet) for 2 months but didn't help.
January: Did blood test for allergies and negative for everything.
February: More blood testing (everything normal). Vet did ultrasound of gallbladder and liver (both healthy) and x-ray to check size/shape/position of other organs (all normal), and to check for foreign bodies (none found).
March/April: Been feeding homemade diet of chicken/rice/vegetables and a vitamin supplement. Treats are real food that he's been allergy tested for. It's been 2 months now, and no change.
Not sure of next steps. The vet is as stumped as we are. Wondering if anyone has had a similar experience or any suggestions on other things to try. Any advice is appreciated. Thanks!