I have always been fascinated with the idea of toilet training your cat.

Cat litter itself is expensive if you buy a type that really controls odors. It is also very heavy, and since I do the majority of my grocery shopping on a bicycle, this matters a lot to me.

Some cats are sensitive to various chemicals or dust in the litter itself. These cats can have skin problems or asthmatic attacks. I used to recommend that sensitive cats use real sand, like that sold for sandboxes, but maybe toilet training would be better. The sand is really heavy, does not clump and does absolutely nothing for odor control

Most importantly, unless you use an environmentally friendly cat litter, most of which I have found are less than satisfactory for odor control, you are contributing to landfill pollution with most of the popular cat litters.

So, if you are intrigued with the idea, here are some tips.

Start by keeping the litter box in the bathroom next to the toilet.

Once a kitten is 6 months old and is using the litter in the bathroom regularly you can begin.

Start by gradually raising the height of the litter box by only 1 inch each day. Use newspapers, magazines or phone books to do this. Anything will work as long as the foundation is very stable.

When the bottom of the litter box reaches the height of the toilet seat with the lid up, gradually shift the litter box over the toilet, again, only about 1 inch per day, until the box eventually covers the toilet seat entirely.

At this point, you should purchase one of the toilet training/litter box kits that will allow you to replace the litter box with a small box that attaches to the rim of the toilet bowl under the seat. Use a liner in this box so you can completely throw out the soiled litter each time your cat eliminates in the "toilet."

This way, he'll get used to the idea that his eliminations completely disappear. Over time, use less and less litter in the box. Once you are down to about 1 cup of litter, you can make a hole in the liner and the box and just sprinkle some litter around the hole. Now when the cat urinates, he will hear the splashing of the water, which is something he needs to get used to. Every week, enlarge the size of the hole. Eventually stop using any litter at all.

At this point you should have a pretty big hole in the rim box and pretty soon you can just remove the rim box when you see the cat perching on the rim of the toilet steadily.

Sounds easy enough, but then again, I haven't tried it myself. Do keep in mind that pregnant cats and kittens need regular litter boxes. Never push your cat to move to the next step. If he seems uncomfortable at any point along the way, backtrack to the previous level or hole size and keep it there for a while, while he gets used to it. And, don't forget to leave the bathroom door open and the seat up.

If you can figure out how to get your cat to flush, let me know!

(Dr. Katherine A. Saenger, DVM, owns Bees Ferry Veterinary Hospital and Boarding Kennel (www.beesferry.com) and is a former board member of the Charleston Animal Society (formerly John Ancrum SPCA.) E-mail her your pet questions to vetsaenger@bellsouth.net, and watch the column in coming weeks for her responses.)