I checked my 50 liter travel backpack for my United flights (5hr flight + 12hr flight). When I claimed my bag at my destination airport, I immediately smelled animal pee from my bag.
I inspected my bag and noticed that the bottom part of my bag was soaked with fluids and there were brownish stuff (see the photo). My sweatpants on the bottom of my bag were literally soaked. Clothes and other items inside my bag had water-mark on them. Items on the top of my bag were okay, but had pee smell. The amount of fluids on the bag was not small (see the condensation on the plastic bag). I had a 20 pound dog and I know the amount of pee for a 20 pound dog.

I went straight to UA office and the UA agents were nice trying to help the situation. They agreed the smell and things on the bottom of my bag would be probably from dog(s).

Has anyone experienced something similar to this or does anyone have an idea how it happened?