I had animals throughout all of my life. All. The. Animals. from hamsters & fish to horses. After my kids moved out & took the last dog & cat with them - I found I enjoyed the lack of responsibility. And my asthma got better. I also have a special dog that I miss a lot. She left us 30 years ago. I found that any dog I had after her, was just a dog. Maybe a good dog - but not special like she was. I understood that there was no replacing her. Sometimes it's a matter of love & respect for the pet lost as well as the nuts & bolts of keeping a pet as a senior. Whatever the reasons - you're absolutely correct. It's an individual choice we make.