I have two cats who are 7. They have always got on and about 5 years ago we had a bit of a problem with weeing on the carpet and marking. We bought felliway and it all went away.

Now, having moved (4 years ago! ) I am waking up to the stench of cat wee every morning. Fortunately we have hard flooring and so am able to wash them each morning. I have a problem though in so far as I CAN'T SEE THE WEE ANYWHERE!!

Please help - is one of my cats weeing or could the smell be something else? Its just so odd that suddenly after 4 years they are weeing. I took them to the vet last week for annual jab and told her she sold me more feliway!! Great!! WHAT CAN I DO!!

Are both of these cats male and have they been nuetered?

They are both girls and have both been neutered.

Has there been any change in what they have been eating? Have there been any other changes around your home that might be upsetting to them?

Just one more thing. Are you sure that the smell is coming from inside your home?

They have not had any change in diet and I am 80% certain that the smell is in the home and is wee. I am going to shut them in the kitchen tonight (it is large so don't worry! ) and will then exclude them from the hallway where the smell is. Obviously if there is still a smell and the cats are in the kitchen it will eliminate them from my enquiries!!

The only thing that has been different is that a friend came to our house and brought their dog. The dog was quite boisterous and probably scary to the girls. However, the dog came round and left 5 days before the first smell appeared and we often have my parents dog in the house and there has never been a problem.

I am just so confused really - if the cats are spraying would we not be able to see some evidence? There is only this smell and that seems weird without any puddles!

We live in a city and there are a lot of cats and even foxes locally - we have seen foxes in the garden. Maybe the girls are just scared of some other animals who are in the garden. Do you think I should get the cat litter tray out and just keep them in the house for a few days to help them feel safe?

Sorry that this is really long

Are your cats indoor/outdoor cats? Were they always or just recently allowed out? There is a product called urine gone that comes with a light that you can use to identify where the urine is. For a good size bottle and the light it is about 20 dollars. It really works well. This can be bought, walgreens, kmart,target. Btw directions must be followed exactly for it to be effective. Hope this helps.

That sounds good will try that if this doesn't work.

They used to be indoor cats but have slowly become allowed out all the time. Do you think that this could be affecting them? THey have always been in at night and had a litter tray but they have not had a litter tray for about 8 weeks and so the cat flap is open 24/7 - that said the smell only started last week.

1st thing... get a black light. Cat urine glows BRIGHT GREEN under a black light. It's absolutely unmistakeable.

Has there been a humidity or temperature change where you are recently? A steep change? If it goes from cool and dry to hot and humid, that can bring out old smells, especially urine smells.

When you use the black light, use it anywhere there is soft material (rugs, pillows, mattresses) where you are noticing the smell. Make sure to check the walls too, and the baseboards!

My guess is that while it may be your cats, it could also be an old smell just seeping through--were the floors replaced before you moved in?

If it goes from cool and dry to hot and humid, that can bring out old smells, especially urine smells.

This is very true! One of the cats that I had about twelve years ago used to "do his thing" around the house. To this day, if the conditions are right, I can still smell it.

You might want to look for Nature's Miracle, big white bottle red letters. It is an enzyme that actually consumes the pee once you find it. Cats do pee on walls and furniture so use that black light there too.

And, just to muddle matters more, there are some plants that (at least to me and other people with the same receptors) smell a lot like cat pee. One of the very popular hedge plants, in fact. Used to drive me insane when I went to my car and smelled the pee smell, but could never find any signs. Until one day I was like "duh.. it's the plants!" Bradford pear is another one, although that just smells like sewer and not cat pee.

Good suggestions as to a possible answer to the mystery! I wouldn't have thought of that possibility. Are you sure that you didn't mean "puddle" matters more? :)

My neighbor has a row of Boxwoods that smell like cat pee and it drives me indoors.

Shut cats in kitchen last night. No smell!! Obviously either the girls or someone else is weeing in the hall way. Will keep that kitchen door shut for couple of days just to make sure and then if still no smell will then go back to litter box and feliway! Thanks for all your advice!