Cat urine on any kind of surface is overwhelming, but when it gets in something like a down jacket, the smell can be bothersome. Removing cat urine from a down jacket can be difficult especially if you don't know where it's coming from on the coat. There are several natural products you can try before resorting to using chemicals on your down coat that may ruin the down.
Dab some hydrogen peroxide onto a cloth and blot at the urin spot on the down jacket. You do not want to pour the hydrogen peroxide directly onto the jacket because it can remove the color from the material.
Apply baking soda to the urine-soaked area if still wet. If the area has already dried before you notice it, baking soda will not remove the smell. Allow the baking soda to sit for 10 to 15 minutes before you wash it off with hot water.
Combine 1 part white vinegar with 2 parts water. Spray onto the urine-soaked area and rub clean with dry paper towels. Vinegar has been proven to remove pet stains and odor on several other materials such as down comforters. Apple cider vinegar also works well in removing cat urine.
Sprinkle an enzyme-based deodorizer onto the cat urinated area. Be cautious of the disinfectants that you use before and after you use enzymes, as they can often destroy the enzymes that are working on the cat urine.
Fill a pail with the hottest water you can stand. Mix in 1/2 cup of powdered dishwasher detergent and allow to dissolve completely. Submerge the down jacket completely into the hot water and let it soak overnight. Remove from the pail the next day, wring out excess water and allow to air dry.