I'm so sorry. I know how hard it is, we put our beloved cat to sleep last summer. It is 9 months today and it is still hard. I'm glad your parents were able to spend some time with him before. Our cat was diagnosed as terminal about a month before, she had kidney failure. We returned from a Disney trip and she was sick. The vet rehydrated her, got her eating and told us to take her home and spend time with her and when she got sick again it was time. We did that and were so glad we did.