Make a mixture of baking soda and an essential oil just enough to make it a thick paste brush into stain let sit till dry then vacuum up.

CHeck it out: http://www.hometalk.com/1923414/how-to-remove-pet-stains-from-carpet and http://www.hometalk.com/8310349/q-pet-stains?expand_all_questions=1

Have you tried Natures Miracle?

We've been recommending this product for years and always get good feedback. http://www.123odorfreekit.com/123-odor-free-kit.

Yes replace carpet and paint floor with kilz and train the dog, once trained replace with new carpet. If it's a puppy or an older dog then don't allow them into carpeted areas. Puppies don't know until trained and older dogs my not have muscular power to hold it in until you can take them out to do their business just like humans. We train children and we change our grandparents if they are in the same shape. We place pads on floor for puppies and for our elderly just incase something leaks we place pads on their favorite place to sit.

Hometalk has been invaluable to me in setting up my Pinterest page, take a look around for hundreds of cleaning hacks

odorlogic cleanaway- best stuff i've found for pet stains and odors.

nature's miracle, white/red bottle, organic, I keep it on hand gets stains out

Resolve power for carpets gets out anything -- even toner ink!

powder

Have you tried bleach. I haveBerber, and bleach doesn't do any harm to the carpet.

The Dollar Store - the Green One - Dollar Tree. Orange spray bottle of Awesome Oxygen Orange. I spray it on to moisten, let it set 5 minutes, and wipe with dry towel. I put this on my laundry stains too.

also after scrubbing with the Resolve powder and vaccuming the spot like crazy spray with hydrogen peroxide.

I don't have any dogie stains, but I do have berber carpet and it is an off white, sometimes red clay gets tracked in and I use resolve mixed with peroxide and then I spray straight peroxide on it and let it sit for five or ten minutes and then I use a teflon scrubber on it then I use a towel to soak up as much wetness as I can then I use another towel and set my Iron on hottest setting and I iron it . the iron helps dry it but it will also help lift stains, many times if someone tracks in something that isn't to bad I will just use a damp towel and place that over the dirty spot and then iron it and it comes right out no scrubbing needed.

If you have light colored carpet the peroxide won't hurt it, but if it is dark do a test on it to make sure it won't hurt it, I have used it on brown carpet and it didn't hurt it, but I always do a little test somewhere that is hidden an won't be seen, just in case. Good luck.