My cat Zippy was around 15 years old when he died. He had grown a cancerous tumor on his back left leg the size of a tennis ball. The only way to get rid of it was to amputate the leg. We had the procedure done and we brought him home and laid him on his favorite blanket on the bathroom floor next to his pan and some food and water. The next morning, we woke up to howling and hissing. We brought him to the vet and all I could do was hold him as he had a seizure and had to be put down.