I see a lot of nasty things where I work, so I can withstand quite a bit. Mucous is what turns my stomach. Sorry your girl had to go through all that!
One of the strays we used to feed got pregnant at a very early age. She gave birth to one near our roses, and the poor baby was stillborn. The rest wouldn't deliver. She took off and we didn't see her for a few days. When we finally did see her, she was full of infection, and maggots were crawling out of her. We tried to catch her, but she ran away, and we never saw her again. To say I cried my eyes out, is an understatement.

It makes me so sad that nature can be so brutal. Whenever something horrendous happens to children or animals, it rips my heart out.