It might be a longer process. I had a cat that was 12 and she used the other system with a little hesitation. I went to the Litter Kwitter with my new kitten because it is sturdier than the competitive product. it's worth a try with an older cat.

1) I would not recommend having a litter box available to your cats. 2) I, also, would not recommend investing in two kits or toddler toilets as you may end up confusing your cats. Start with the box beside your personal toilet and slowly raise it as the cats adjust. Phone books work well. Also remember that each cat may have its own learning curve. I would go as slow in your training as the slowest cat adjusts. In other words, don't raise the box until all of your cats are on board. 3) Were they even meant to be questions. ;)

By handicap I assume you mean ADA compliant which only refers to the layout of bathroom stall or compartment. All toilet seats are a standard width. There are longer toilet seats available but those are specialty items & you would know if you have one. If you do have a specialty toilet this may not work because it's designed for a flat standard size toilet.

This was not an issue in my experience. It's my son, my husband, my cat and myself. We all use the same toilet. Of course, every cat is different so don't quote me.

I used Better Ways Cat Litter, but I can't find it at Petco.

If they are old enough to litter box train then they are old enough to toilet train seeing as you start with the box and just raise the box as they adjust to the new height.

If they are old enough to litter box train then they are old enough to toilet train seeing as you start with the box and just raise the box as they adjust to the new height.

There is a booklet and dvd to get you started, but I began by putting the regular potty box in the bathroom and leaving it there for 3 or 4 days, then adding the Litter Kwitter by placing it on the floor, first next to the potty box, then by sliding it over next to the toilet. For a day or two, it stayed like that, then I removed the potty box and put the "kitty potty seat" up on the porcelain bowl, not the human toilet seat. And, yes, it will work on round or oval. You just place or remove the clips as necessary. I have 2 little girls who are doing just fine, though one is moving at a slower pace than the other. So, just in case, I bought the supplemental pans so that Hannah will feel just as comfortable as Delilah. It may take a little longer that way, but I'd rather get it right the first time! Oh, and make sure that you use flushable litter, like World's Best in the red package. Otherwise, you could have a big mess on your hands!

I have a 17 pound cat, and he didn't have any problems with it. I don't think another 3 pounds would break it.