Despite popular belief about aircraft having limited airflow (and the corresponding myth that airlines limit fresh air to reduce fuel consumption), the cabin air on modern aircraft is completely changed about as often as in modern office buildings. There have been several threads on FT in the past few years where the data have been presented.

That said, I can sympathise with you and your allergies. I share some mild allergies to cats (never noticed any reaction to dogs, but maybe I just don't realize it). And you are correct, the allergens will probably persist even after the animal has disembarked.

But here's my difficulty with this issue: Disabled people will be able to fly with their service animals whether you like it or not. I have even sat next to individuals and their guide dogs. And, presumably, your allergic reactions are the same to the service animals as to the pets. Since you can't prevent the service animals from flying, why attempt to restrict passengers from bringing pets? You'll itch and sneeze and respond the same no matter the relationship of the animal to their owner (pet or service animal).

Analogies to the peanut allergy appear misplaced to me - I have never known of any pet allergies to be as potentially fatal as allergies to nuts, but I certainly don't know everything.

I'm not happy sitting next to smokers, nor people wearing excessive amounts of perfume/cologne, etc. I would prefer that people on the Continent generally be as meticulous about bathing and body smell as Americans generally are. All have the potential to make me feel ill.

But as others have pointed out, offensive smells are everywhere, even on airplanes.