Domestic cat tail quivering when spraying urine to mark territory

There is a discussion among a certain section of cat lovers as to why domestic cats quiver their tails when they spray urine against a vertical object to mark territory. Not all cats do it or they don't do it all the time. It is, however, very noticeable when it occurs.

Spraying urine horizontally to make territory on a vertical object. Tail quivering can accompany the process.. Picture: Pixabay (modified).

Not even the experts understand the reasons why this happens. It may simply be just a part of the physical process of spraying urine. My personal opinion is that if a cat is quivering her tail when spraying urine it is because it is a manifestation of the effort to spray urine at considerable force against a vertical object. It may even be part of the process of forcing the urine out of the bladder.

This is a common sense reason for it and it ties in quite nicely with the actions and behaviour of humans when trying and force things. When people force things they push and shove and repeat their effort until it happens. Tail quivering is not dissimilar. It probably simply expresses the urine from the bladder and down the urethra more quickly and efficiently.

Experts say that when captive wild cats quiver their tails when spraying it occurs when the spraying is particularly vigourous. This supports my thought on this rather specialist subject. Black-footed cats have been seen to do it and it goes hand-in-hand with treading of the hind feet which you also see when cats spray urine. Hind feet treading is also a visible manifestation of the effort required.

There is an alternative reason which is perhaps far-fetched. I can remember a cat that I rescued from the streets of London many years ago. She was under a car. When she saw me her tail quivered in exactly the same way. It quivered because she was pleased to see me because I spoke nicely to her and ultimately adopted her. She knew that she was being rescued. I wonder if tail quivering during urine spraying is a sign that the cat is enjoying a pleasurable moment. In other words tail quivering is an expression of pleasure as urine spraying might also be pleasurable as well as purely functional.

All cats do this both wild and domestic.