Dog allergies but no symptoms? Possible?

I've had a dry cough for a couple of months and went to the allergist to try and track down the cause. I was allergy tested and the only thing that came up positive was dogs. BUT I've owned various dogs - all big, heavy shedders - for more than 20 years and volunteer with a humane society and never had an allergy symptom I can attribute to them. They sleep in my room (not on my bed), they are in the house and with me constantly. My recent cough is actually better in the morning than in the evening despite having dogs in my room all night. I was prescribed Singulair and it is helping the cough quite a bit.

The test also doesn't explain the seasonal allergy symptoms I have each spring or the asthma reaction I once had to a moldy environment. In fact, none of it makes sense.

Is it possible to be allergic to something you are constantly exposed to and have no symptoms at all? Even the doctor doesn't think this is the whole picture. I see him again next week. Can anyone explain?

Sometimes your body might just get use to is but its still allergies!

Very possible. I had been around cats and dogs for many years and then I started getting hives we could not figure out what I was breaking out so bad from it was bad enough my face would swell. When I moved out of my parents about 3 years ago the hives went away along with the face swelling. Because I live in an apartment I cannot have cats and dogs. But as soon as we get a house I will be getting some so I will have to go back on zyrtec.

TAKE AIRBORN! it works