Nanogirl Michelle Dickinson: Your venomous house pet

Your feline best friend may be more dangerous than you think. Photo / 123RF

An estimated 10 per cent of us are allergic to household pets, with cat allergies being twice as common as dog allergies. New research out this week might help to explain why cat allergies are so high with a bit of help from the very cute endangered animal the slow loris.

Slow lorises are big-eyed, soft furry creatures native to the rainforests of South and Southeast Asia. Loris is Dutch for clown and it's thought their name came from their distinct facial features which almost look painted on.

Being able to remain totally still for hours on end means they live up to the "slow" in their name. Though they may look cute and harmless, if threatened the slow loris is able to defend itself by licking a gland under its arm and mixing it with saliva to give a not so adorable toxic bite. In the few documented cases of a human being bitten by a slow loris the victim is reported to go immediately into anaphylactic shock – a severe and often fatal form of allergic reaction.

This allergy-inducing bite is unique to the slow loris and they are the only known primate with venom. In nature they use it when fighting other slow lorises to inflict very slow-to-heal wounds on the other animal. They also spread the venom all over their bodies, which is thought to ward off predators.

As an endangered animal there have still been very few research studies carried out on the creature, and little is known about its unique and dangerous venom.

Researchers working at a wildlife reserve in West Java in Indonesia managed to get hold of some of the venom from animals living there and analysed the DNA sequence of its proteins. Unexpectedly they found that it was identical to a protein also found in domestic cats and in their new study published in the journal Toxic this week they hypothesise that domestic cats might actually be venomous.

It is thought that most people who are allergic to cats but not other furry creatures are actually allergic to a protein in the cats' saliva rather than the fur of the animal. As cats love to preen by frequently licking themselves they leave behind a thin coating of this protein on their coat which can trigger an allergic response to those humans that are sensitive to it.

This new discovery led the researchers to the theory that cats might actually be using their allergy salivary protein as a defensive weapon in the same way the slow loris does.
Now the question is whether or not evolution meant that both the cats and the slow loris that produced the allergy defensive weapon were more likely to survive and therefore pass on the protein, as it kept predators as far away as possible.

With humans' allergy to cats being so prevalent, the new research definitely points to them evolving a defensive weapon in a similar way to the slow loris and helps scientists to further understand animal induced allergies in humans.

The researchers from this study are now interested in studying venom variations in other creatures like bees and ants to see whether they are part of the same evolutionary tale.

Though the research wasn't able to suggest any ways to cure our allergies to cats, it might be fun to let your children know they can add "venomous saliva weapon" to the "scratchy claws" feature of their feline friend. For now the advice for cat allergy sufferers remains the same – wash your hands after touching them and take an antihistamine to relieve your symptoms.

Dr Michelle Dickinson, creator of Nanogirl, is a nanotechnologist who is passionate about getting Kiwis hooked on science and engineering. Tweet her your science questions @medickinson