Mice urine has a pungent smell. When this smell gets into carpeting, furniture and wood floors it can leave a permanent, intense odour that will linger in the whole room. Fortunately, you can get rid of the smell without resorting to expensive treatments and toxic chemicals you may not want to use to clean your house or your pet mouse's cage.
Rent a carpet steamer if you don't already have one; you can rent these from building supply stores for about £19 a day. Add carpet shampoo and follow the instructions for use on the steamer, remembering to empty the water container as it fills up. Go over the carpet a few times if the smell is really strong.
Mix a solution of equal parts white vinegar and water. Add a few drops of essential oil such as eucalyptus or lemon. Shake the bottle and spray on the area with the bad smell. Let it sit for a while, but don't let it dry out yet.
Cover the affected area with baking soda. Rub it into the damp carpet or rug over the vinegar solution. Alternatively, you can add one or two tablespoons of the baking soda directly to the water and vinegar mixture in the spray bottle. If you're using this on a wood floor, mix the baking soda in the spray bottle with the water and vinegar instead of rubbing it into the floor. Spray the solution on the floor, and leave it there for a couple of hours before wiping it up. Vacuum the rug or carpet once dry. Use the baking soda and vinegar solution to clean your mouse cage once a week. Let it dry and add clean bedding material.
Rub into the carpet or rug a mixture of any dish soap (just over a teaspoon) and 7 fluid oz. of 3% hydrogen peroxide, if the smell is still there after the baking soda and vinegar treatment. You can apply this onto the baking soda while the carpet is still damp. Applying it onto the baking soda will make it easier to remove afterward, since the dry baking soda will act as an absorbent.
Steam clean the area after you have let it soak in the baking soda and vinegar mixture for a while. Do this step if the odour problem was especially bad. Otherwise, just wait until the area dries and then vacuum well.
Wait a couple of days and see if the smell of urine has gone. If it's still there, you may need to repeat the process.
Alternatively you can also clean your pet mouse cage with a mild bleach and water solution.