My cat does its business in my neighbor's flower bed. Their dog finds it and gets sick. How can I train my cat to go on my property? I got some sand and made an "outdoor toilet", but he isn't using it.

Things cats hate
Landscaping.about.com

Rue, lavender or coleus canina around the borders of your flower beds

Sprinklers that have motion detection
Scarecrow Motion Activated Sprinklers | Using Scarecrow Sprinklers

Citrus
Cayenne pepper or chili powder

Chicken wire on the soil. They hate walking on it.

I've had this problem for years with the neighbor's cats. I tired plants that were supposed to repel cats, supersonic alarms, plastic nubby rug protectors, etc. Nothing worked. The only thing that helps is for you to keep your cat indoors, or find a cat enclosure for it. Your cat's desire to roam should not trump your neighbor's right to enjoy their property.

I'm not sure if you would want to go through all the trouble but maybe you can make a flowerbed in your yard for the cat. Just a small patch.