Cats are much more trainable than many owners realize and if behavior problems do arise they can often be dealt with quite simply so long as you take the time to see the world from your cats point of view.
Cats of both sexes sometimes spray when they feel insecure. By establishing a sense of their own smell their confidence is boosted.
Spraying can become a problem if you cat starts to spray furniture and curtains. The first thing to look at is the reasons why cats spray .Both sexes spray and neutered males are just as likely to spray as un-neutered. Normally cats do not spray indoors as they feel secure and there is no need to protect their territory. When several share a house they may feel the need to mark their territory. If the spraying has suddenly started look for some changes in the house hold that could have caused stress.
For some cats this could be the installation of a cat flap. This blurs the distinction between the indoors and outdoors and the cat needs to mark its smell.
Some owners spray pepper or chili or wipe the areas with vinegar but this does not really work. You can try to place a tray of marbles below the favourite spraying places but if you cat is determined he will just stand further away.A good idea that can work is to put a sheet of household foil around the spot as cats do not like the sound of urine hitting the foil.
The psychological approach may be more successful.
If you have more than two cats try giving each a separate place to sleep in. If a neighbour's cat is always lurking outside then chase it away.if you have installed a cat flap try boarding it up and see if the behavior stops.
In difficult cases confine the cat to one room and make sure it has a cosy bed under a radiator and its toys. Make sure you do not leave it for too long and its sense of security will increase. as you see the situation improve let is use more rooms of the house and keep an eye on it. Lastly if none of these strategies work then see your vet about hormone treatment.
Kathy lectures in Human and Animal Health and behavior.