Dog throwing up yellow bile

hi -

i am new to this group, but the reason that I am writing is because my
rescue dog is frequently throwing up yellow bile. Three months ago I
rescued a German Shepherd/Belgian Malinois mix (city stray) and when I
first got him he had serious itching/biting - I figured allergies. My
regular vet put him on what ended up being 2 rounds of Triacimaolone (a
form of steroid) until the weather changed (we live in MD) to see if he
was having seasonal allergies. The drugs worked, but as he came off the
last round he started throwing up yellow bile all of the time. For the
first couple weeks it always happened two times, one right after the
other and its always been yellow bile. Now its only happening once at a
time. I have had bloodwork run and he is currently on Hills Z/D
(allergen-free food). 2 weeks ago I took him to the allergist thinking
the throwing up might be allergy related (he has started itching again
and has mucous in his eyes) but the allergist referred us to an
internist. The internist did a thorough exam and did an ultra sound and
found nothing. I've done lots of research on the net and did stumble
across something where people feed their dogs at bedtime to keep the
dog's gastric juices from causing nauseas. Last night was the first
night I have tried and he did not throw up this morning, but that does
not necessarily put us in the clear - he doesn't always do it everyday.
And although a good majority of the time he throws up in the morning,
that's not always when he does it. Like yesterday, he threw up in the
afternoon. The internist wants me to get him scoped and I've scheduled
it for Thursday. I just want to make sure I'm doing the right thing and
that the scope is a worth while procedure or if someone else out there
has a dog who's been doing the same - I'm just very afraid they are
going to scope him and find nothing. I have seen 2 instances now where
a dog has had skin irritation and throwing up and maybe there is a
relationship between the two. ANY help would be greatly appreciated!!!
Jenn

Jessica -

What kind of food is your dog on now? I had started him on Nutro
Natural Choice. Then when I realized that the itching was more than
just dry skin, I switched him to Solid Gold Hunden-Flocken - a more
natural food w/ minimal allergens in it in case he had food allergies.
It was while he was on that food that he came off the steroids and
started throwing up. So we changed his food yet again to the Hills z/d
in case the throwing up was allergy related. He's also been off the
steroids for a month now, so I'm not sure at this point it could still
be a reaction to that? We tried giving him Benadryl for his allergies
(well it was a generic antihistamine Equate, recommended by my vet) and
they didn't do a thing for him. The only thing that helped was the
steroids. I have been strongly thinking about adding a fatty acids
supplement, but wanted to wait until the throwing up ceased before
doing anything else to his diet, at this time he only gets his food.
Thanks so much for your response, I appreciate it!

Jenn