catmom, with all of Sophers poo-poo problems we had the same issue.  We found a carpet shampoo that we put some in a spray-bottle mixed with water and it has worked extremely well, so far I havent had one spot that didnt clean up.  We also used it for small throw-up areas. It can also be put in carpet cleaner machines for bigger areas.  Its called AFM Safechoice carpet shampoo.  This is the description and the link to it, although its carried at a bunch of other places as well.

   Odorless, dye-free rug/carpet shampoo is non-toxic, non-corrosive, non-flammable and biodegradable. It will not irritate eyes or skin. It's a strong cleaner and odor remover, yet safe. Contains no harmful chemicals like ammonia, butyl ethers, alcohols, phosphates, caustics or acids. Can be used instead of toxic shampoos in steam cleaners.    http://organicgrace.com/node/204

I forgot to add that we spray it on, almost saturating but not quite and then take a wet sponge with hot water and scrub it and then go over it with another wet sponge to rinse it and then blot the area with paper towels.  Sometime we have to do it a few times depending on how bad the soiled area is, but its has worked beautifully for us.  I do not remember the ratio of the cleaner to water we used in the spray bottle though, I could double-check with DH.

ETA: Double-checke with DH and he said he used about 3/4 to 1 oz of the cleaner in a spray bottle that holds 8 oz...so you dont need much at all.  And as always you should do a spot test first but our carpet handled it just fine.

For cat urine the best treatments we've found are Nature's Miracle Just For Cats, and Get The Odor Out.

I prefer Get The Odor Out if pulling up the carpet is possible.  Excellent for urine spots that are right near the edge of the carpet.  Pull up the carpet, soak the underpad and the back of the carpet with the spray full strength.  Put the carpet back, leave it for 48 hours.  Then dilute according to instructions and treat the front of the carpet.

If you can't pull the carpet up to use it full strength, we use Nature's Miracle JFC.  However, for actual visual spots on the carpet, we've found Simple Solutions Stain and Odor Remover to be the best.  I've gotten out urine, diarrhea, blood, vomit and even ink using this product. 

Sound like a testimonial yet?  lol

Could be because when we were still doing cat rescue we topped out at 22 cats in the house (several of them were kittens) and subsequently we went through a LOT of odor removers.

There is a difference - the Just For Cats is specifically designed to handle the chemical makeup of cat urine, which as we all know is much stronger and long lasting than dog urine.

Also, the Just For Cats is more about odor remover - stain removal is better with other products.

Catbird, I also have used the Nature's Miracle Just For Cats and have had good luck with it for removing the odor.  Resolve does work very good with the stains as 3cat mentioned.

I'm going through a lot of the NM, but wondered now about a small carpet cleaner? Bissell has several, but a couple of them are over $100 so I'm asking if anyone has used any kind of a carpet cleaner. I have my carpets cleaned by a professional (my house is on a slab in cold, cold Michigan - hence much carpet) but would like to get the ever increasing number of spot removed IF possible.

thanks

OxyClean does a terrific job of getting out stains and is not toxic to grass - reason I throw that in is I used it to clean the wood on my deck and it brought the wood back to the original color (looked brand new) again and I was so impressed. Had to rinse it down and it went into my grass below the deck and not one blade died. Have removed coffee stains, blood, grease, ground in stains from a front carpet mat in my old '84 Riviera that had been in there for years - took it all out. You can make up a lil in a small bottle, apply it,  blot it out, rinse w/cold water and your done. I use the original for stains and the dollar section one from Jewel for cleaning drains out as it is easy on the nose.

Lots of other uses for Oxyclean are listed on the container. Can be used in your laundry too.