We had that when we had cats but it was in the bottom of our wardrobe and on steves shoes
, trouble is it stinks but you cannot see it, also one used to pee on the stairs in a courner, never got rid of that stain or smell.
The worse one was our little Patterdale, we bought a nice Ikea rug that was greens and long pile, as I walked over it without shoes one day I noticed a wet patch, then several more wet patches, I tried every thing and spent a fortune, when we moved I cleaned it and rolled it up, when unrolled the smell of amonia was terrible so it just had to go..
I would say your suitcase may have to go too
Hope not but good luck anyway