My cat Marvin is a stress boy who sprays. I have used these diffusers and Feliway for years. They work...Marvin is proof. If I get lazy and forget to change the diffuser (they last 5 weeks) I find accidents.

Pros: easy of use

Cons: expensive

At the time, I had just introduced 2 new adult cats. The two cats living in the house at the time did NOT appreciate the new cats, and there were a lot of hiss/scratch fighting going on. Especially around the spiral staircase and at the door to the laundry room (litter boxes are in there). Then at least one of the cats started peeing on the carpet on the 1st floor. BAD NEWS!!

On the advice of our vet, we decided to give this a try. We placed 3 on the 2nd floor and 2 on the 1st floor. We did see a marked reduction in fighting and arguing.

It reduced the peeing on the 1st floor, but it didn't stop it entirely. The responsible kitty had other health issues and eventually found a new home at my vet clinic. She eventually died too young due to a stroke probably brought on by years of monthly steroid shots for her very severe allergies (nothing else ever worked).

Pros: Easy to use plug in diffuser

Cons: Sticks out from plug quite a way

Feliway is an effective way to calm stressed cats. If you are experiencing a urine marking problem, Feliway can help stop the behavior, and support other efforts to stop it. Not all cats will respond to it, and may require other intervention to stop the behavior.

Pros: Calms stressed cats

Cons: Not all cats respond

Does it work? May be. Like anything else, whether it works depends on the cat and the circumstances.

While we do not currently use it, we did use it for a few months during a time of high stress for our cat. We think it helped keep him calm and well-behaved during a time we feared would cause him to revert to peeing everywhere but the litter box. We had previously used the feliway spray and did not think it was effective in our case.

We would not hesitate to use the diffuser in the future, should circumstances change.

One note, we had it plugged into the top plug of a two plug wall outlet. Another plug was plugged directly below it. We discovered that an oily residue developed on the lower plug. But other than that, the diffuser is quiet and does not give off an odor. Visitors generally thought it was an air freshener.

Pros: May help calm kitties during times of high stress

Cons: Expensive

We have 12 cats that are indoor outdoor cats, all spayed or neutered. We have never had a problem with spraying, until recently. Our 2 three year old female cats, litter mates have recently started spraying and peeing in odd places. After ruling out veterinary problems, we decided to try Comfort zone w/Feliway. Let me just say the cats sprayed and urinated on the counter less the 3 feet from where it was plugged in. It didn't work for us at all and it was very costly to purchase. If you have one or two indoor cats with minor marking problems, in a smaller house, maybe it'll work, but it did nothing for us.

Pros: Easy to use

Cons: Didn't work, used up an outlet