Asked by: Glyn Wogan, Monmouthshire
Some do, but more rarely than humans. Hayfever in humans is a side effect of our ‘adaptive’ immune system, which remembers previously encountered foreign molecules, such as those associated with disease-causing organisms. That sensitises us, so we respond immediately on meeting these organisms again.
Unfortunately this system can also become sensitised to innocent molecules, such as those found in pollen. Adaptive immunity is common to all vertebrates, and hayfever has been documented in dogs, cats and horses – possibly because of their greater exposure to parasites. Similar reactions to innocent molecules are possible in chickens, although the exact response differs, and something akin to it even occurs in fish.
However, invertebrates such as insects and worms don’t have adaptive immunity, so if they have allergic reactions, they will probably be unrecognisably different.