My cat reciently had to be put to sleep. He had Auto Immune Disorder. He was born with it. It is where the his immune system started to attack the body. We tried everything. Every shot-medicine. nothing helped and he was in so much pain and was suffering so much. He lost his fur. It got to where he couldn't breate so my mom said she would take him. We all knew it had to be done. I felt like so bad-Like I hadn't spent enough time with him.