This is about domestic cats using their sense of smell to identify other cats even when they know each other and with whom they are normally friendly. This scenario has been discussed on two major websites, mumsnet.com and quora.com. I would like to add to the discussion if I may. The scenario is this: Mr and Mrs own two cats and they move home. Prior to moving home, their cats were friendly. After they moved home one cat hisses at the other. To all intents and purposes, it appears that they no longer recognise each other or one cat doesn’t recognise the other.
Domestic cats recognise each other through visual identification and also, and importantly, through the scent of their body i.e. their body odour. My experience tells me that body scent as a form of identification is more important than the visual one.
If a cat cannot identify another cat by their body scent, they will become a stranger even if they were friendly beforehand or even if they are a close siblings. It is that clear-cut. A cat can go from being a close friend to a complete stranger just because they smell differently.
And for me, this gives a clue to the answer as I see it. On the mumsnet.com website the cats’ owner said it was as if her ‘big cat’ could no longer recognise the smaller, female cat. This is probably because the female cat had rested or rolled on something in the new home and taken from that object an unrecognised scent which was deposited on their fur.
The big cat could no longer recognise her and therefore hissed as if she was a stranger. If the cat that picked up the scent was wiped with a damp cloth, I would suspect that the other cat would then recognise them within about 30 minutes.
You get a very similar situation when one cat of a pair who are friends with each other falls into a bath tub full of water. They become drenched. You take them out and dry them off and in doing so you remove all their body scent. The other cat can no longer recognise them and hisses because they are a stranger. It looks very odd because for years they’ve been friends and they might, as mentioned, be close siblings.
And then the cat who fell into the bath tub grooms themselves and in doing so they deposit their scent back onto their fur as the sebaceous glands produce oils. After about two hours or so the other cat then recognises them and all is well again.
The identification of anything, be it another cat or food or any other object, starts off with smelling it to confirm what it is. The scent of an object is the final check, the absolute check and if it doesn’t pass the test the object is alien to them.
Every time that I feed my cat with food that he knows very well he sniffs it before he starts to eat. It’s the final check to ensure that it is edible. In fact, he sometimes stalks it before smelling.
Domestic cats smell their owner all the time because they like the smell as it comes from their owner with whom they are friendly and upon whom they rely and because it is a reassurance of identification. Domestic cats have poor eyesight in terms of optical quality which is about a third as good as typical human eyesight.
It is not that great in terms of definition. Although it is good in terms of capturing light under dark conditions but that is another matter. This is perhaps one reason why they rely so heavily on the smell of objects.
It is not a good idea to bathe a cat living in a multi-cat home for the above reasons. Although there will be big variations in response. I am sure that there are occasions when a change in body scent does not phase another cat.
Below are some pages on a cat’s sense of smell.
