Yes, You Can Train A Cat To Go In The Toilet
Changing cat litter can be a drudgery for sure. The smell, the mess, the yuck of it all can really get to a person. Even with those automatic litter boxes (I didn't like them too much) there is still smell, and yuck.
Another option is to train the cat to go in the toilet. It is a process and will take a bit of time but it can be done.
The idea is to start moving the current litter box toward's the toilet. If you have a sensitive and fussy cat this can be a slow process. Some cats will let you move the litter box easily with no fuss or problems. If you try to move it quickly, be sure to block the cat's way into the usual spot if possible. Be sure to also show the cat her new spot. Hopefully, you can have the litterbox at the base of the toilet soon.
Once the litterbox is beside the toilet you can then move on to the next part...check the instructions on how to train your cat to use the toilet at Ehow (one of my favorite sources of info.)
There are some useful kits that can help you train your cat to use the toilet called Litter Kwitter or Citi Kitty. (no these are not ads) You can find these items online, at some super stores and at the pet store.
There is a downside to training your cat this way. There are several reasons one may not want to choose this method. This is not a natural thing for your cat to learn. It can be a problem if the cat ever falls into the toilet and makes the cat afraid to use it again. As the cat ages, arthritis can be a problem and make it hard for an older cat to jump. There is also the issue of floaters and urine left in the toilet after the cat is finished (not to mention if the cat misses the hole.) I have heard of cats being trained to flush too. I decided not to go this direction with my cats because the toilet that would be used is also the toilet my company uses. Here is a video showing that yes, it is possible to train the cat to flush the toilet too. This is Quiz the cat using and flushing the toilet.
In the end, for me it was a better choice to train my cats to go outside and to have a hidden litterbox in a nice side table that I ordered on the Internet. I placed it in an out of the way spot with a vase of flowers on top. My only problem at the moment is Miss Kitty keeps tracking litter out with her...(big sigh).
You have the facts now, that yes, you can train your cat to use and even flush the toilet. Now you can make an informed decision about what is best for you and your cat.