Reglan is made to clear the stomach fast. I would get your dog off that stuff. Its banned in humans. It used for Mega E dogs. It gives you the runs and fast.
A combo of all those drugs together would make anybody lose an appetite.
Google all those drugs and see what they are for. They are drugs given to Mega E dogs. I never heard of one getting them all at once
High white blood count is so hard to determine what causes it.
And I am not so sure any of those fake, no active ingredients, prescription foods are any good. The ingredient content with rice and corn does not seem very digestible to me.
You may want to look into a specialist vet or depending where you live, some great vet colleges have great clinics.
Good luck hope the dog gets better.