I have a feeling that since they had increased their water intake that they might have both had some illness that caused them to want more water and therefore they might have been close to the end of their lives anyway.

You could have done what I did! My daughter had a hamster. I had read somewhere that hamsters could eat lettuce or celery but not green peppers. the peppers would kill them. I forgot about this most important information. One evening I was making dinner and gave the hamster some green pepper. He ate it that night and was dead by morning. I then found the article that said that peppers caused a painfull death. I have felt bad ever since but have never told my daughter....I also ran over my cat one dark night when she was laying behind the wheel of my van. I know she was old and not well, I had had a conversation with her about not sleeping in the driveway as someone would run over her and I didn;t want to be the one to do it. I guess it gave her an idea on how to get the suffering out of the way. Man did I and do I feel bad I loved her so much.