intestinal issues run in this breed.
Sounds like your dog could have inflammatory bowel disease in the small intestines.
Was there anything off on the blood work like lipase and amylase were they high as dogs with ibd can test high on those two things.
If blood work is fine and doing this then that would be my guess is ibd as either those two things are high or everything is perfect.
Inflammatory Bowel Disease in Dogs
The hills i/d has pork in it. Sometimes ibd dogs have to be rotated on food once the upset happens again.
What food did you feed when this all started? I would stay away from any chicken diets. My dog has ibd and he is on purina ha so you can try that and another one my dog did good on was ultra z/d by hills as both are hydrolized diets but ultra z/d has chicken in it but it is hydrolized which is a broken down form of the protein.
If you want to try a non-vet food then venison is usually a good choice so you may want to try natural balance venison and sweet potato.
Another thing to ask the vet about is using tylan powder as that is a antibiotic but the most mild one and it has an anti-inflammatory agent to take inflammation down in the intestines
Before doing anything like steroids the vet or internal medicine specialist will do endoscopy to see if it is truly ibd as they scope them then biopsy intestines. I never had to do this as the food worked for my little guy so hopefully you can get this under control with that as well.
Probiotics also can be helpful with these cases but food is going to be key.
Also dogs with ibd in small intestines are more susceptible to pancreatitis so low fat diets are highly recommend for these little ones.
When my dog had pancreatitis hill's I/d made him relapse so i am not a big fan of that food
If the prescription diets do not work then homecooking will be the next step as well and i would do all this before using any drugs like steroids. Steroids should be your last resort.
Any diarrhea going on?