How it is that animals understand things I do not know, but it is certain that they do understand. Perhaps there is a language which is not made of words and everything in the world understands it. Perhaps there is a soul hidden in everything and it can always speak, without even making a sound, to another soul.
When we adopt a dog or any pet, we know it is going to end with us having to say goodbye, but we still do it. And we do it for a very good reason: They bring so much joy and optimism and happiness. They attack every moment of every day with that attitude. The average dog is a nicer person than the average person.
Cats know how to obtain food without labor, shelter without confinement, and love without penalties. Cats have it all: admiration, an endless sleep, and company only when they want it.
It's difficult to understand why people don't realize that pets are gifts to mankind. Pets have more love and compassion in them than most humans.