Removing pet’s residues is not an easy task and should not definitely be done by spraying antibacterial solution on the carpet and the scrubbing it, this will only get your carpet more stained and will make the problem worse. Furthermore one should always avoid over moisturizing the carpet, as this can only make problem worse by spreading poo in to your underlay and even deeper if way to much water will be used.
Solution: using antibacterial solution, like dettol or equivalent chemical mix it with mater (make sure that your carpet will not discolor under the chemical, You should always test the solution on some carpet sample that will not be visible and you don’t mind having it bit lighter or otherwise not evenly colored.
Once you have the solution done and your carpet testing is showing that carpet will withstand solution you can start working on the stain with solution and sponge that will extract as much poo as you can. Once no more is coming off, simply sprinkle the stain with your solution and then sprinkle it with backing soda (backing soda will absorb much of the chemicals and poo). One this had few hours to dry out, simply vacuum the surface and repeat the process until you are satisfied with results, it will take some time to get tot pristine condition.
If you are living in Wales areas, you can also cal specialists dealing with carpets cleaning: you can find one at www.dmcarpetclean.co.uk