It's not just us humans who suffer from the effects of the summer. Our furry friends can also react badly to tree pollen, grass pollen and weed pollen - the three big causes of human hayfever. In cats and dogs the symptoms usually result in itchy ears and skin rather than respiratory problems, like running noses and sneezing.
However, over the years I have met far more humans who are allergic to their pets than pets with allergies. So what is it with humans and our inability to cope with the world around us? This could have something to do with the sterile lives humans insist on living - if we're not exposed to dirt when we're young to prime our immune systems, we can start to suffer over-reactions to normally harmless substances such as pollen.
In addition, humans, unlike other animals, don't get many parasitic
infections (at least not in western countries). It's thought that
the immune system is kept in check by parasites, stopping it from
freaking out when it encounters something like pet hair, pollen
or dust.
