That's the good and bad about pets... they'll give you years of enjoyment but the end is rough.

I went through a period of 1.5 years where I lost 2 cats and a dog. One cat was 10 years old, wound up with bone marrow cancer, and let me tell you, there's nothing worse than watching 6 months of deterioration of a loved one. The other two were more age related, an 18 year old cat and a 14 year old Irish Setter, both just got to the point where it was obvious they had a hard time existing, and the decision was fairly straight forward with vet recommendation (though only one made it to euthanasia).

It took another 1.5 years before I would entertain another dog, and now we have a 4 month old lab mix from a shelter and sleep and peace are tough to come by. 16 years since I had to raise a puppy, and now I remember why 10 cats are 10x easier than 1 dog!