I was allergic to one of my parents' cockers Rusty with the same symptoms. Everytime I went to visit, I had the symptoms and ended up looking as if I'd been punched in my eyes. When Rusty died, I could visit without any problem and didn't have a problem with any of their other cockers.
However, Rusty could come and stay in my house for a week at a time with only a slight eye itch for the first day, even though he slept in my bedroom next to the bed. From that, I believe it is a combination of house and dog that causes the problem. My house is an old terrace, high ceilings, no double-grazing and very 'airy'. My parents' house was a recent new build, double-grazing and frankly, in my view, did not allow enough air to circulate - mound in the bathroom, mound on the double-grazing, etc.