How to prevent cat from toileting in my neighbours’ garden?

[SunnySellsShells]

Our 18-month old Tortie had access to the outdoors but always used her covered tray until last summer. We went away and had some friends come over to catsit, and I suspect she didn’t feel safe enough to use her tray (their two children turned out to be quite wild!). She now toilets outside, which I am not terribly happy with. Her tray is clean and at the ready as it always was but she only uses it about twice a month tops (usually when it’s very wet).

This morning I was horrified to catch her digging our lovely neighbours’ front garden. I don’t know if it’s a recurrent thing - I had never seen her do it before - and I am mortified. Is there anything I can do to induce her to use her tray again? I thought the could would prove an incentive but so far it hasn’t worked.

Jackson Galaxy often talks about using motion-sensor activated water sprays to disincentivise behaviour. I would be happy to buy one for my neighbours, but the ones I found online were all very bulky and are attached to the water hose so potentially more a waterfall than a spray…

Any suggestions/recommendations very welcome, thanks :)

Keep her in until she gets used to using her tray again?

A picture of the cheeky madam...

Leave a tray outside as well as one inside.

Make a patch (min 2ft square) of lovely soft, plant and stone-free earth in your own garden. She should then choose that over any other place.

@babymamama your suggestion makes complete sense. Has anybody tried keeping their cats in to retrain them to use their trays rather than go outside, and more importantly, has it worked?

The challenge will be that she loves going outside and it would be very difficult to keep her in all the time. She is very good at escaping!

@sallygoroundthemoon Good idea! It would have to be outdoor-proof, right? Would other cats use it? And how can I convince her it’s the more attractive option? We use cats best and never had any issues before the summer.

Thanks @thecatneuterer. I have suggested it to my DH but he seems reluctant, I will try again. As above, would other cats use it too? I imagine so?