Selfsufficientish.com

For no apparent reason, my adult male neutered cat has started spraying indoors. What are the possible causes?

Could another cat have got in the house? I had an intruder through the cat flap and my tomcat was not impressed. My stair carpet did not smell good at all after he flew down the stairs in pursuit.

JuzaMum

A change in behaviour is often caused by a change in circumstances. Cats spray to mark their territory - so has anything happened to cause him to need to mark his territory all of a sudden? As Juzamum says, another cat around (even if not in the house) would be a possibility as would a new pet or baby, a stranger in the house or a visiting dog. If you can pinpoint a temporary cause, then the problem might clear up when the cause ceases.

Zoe

Stress is a common cause of spraying, but first thing to do I've been told is run to the vet and check for urinary tract issues.

Perhaps this gives a few clues? http://www.vickyhalls.net/feline-faqs/4566063347

Good luck. It is no fun having a spraying cat (been there, done that)