I just finished reading Waiting for Normal and loved it. The MC has a hamster for a pet and there were several times when I thought the hamster was dead meat, but it survived the whole book.
When I was in 4th grade, my teacher read Island of the Blue Dolphins to us one chapter a day. I cannot remember the MC's name, but I remember feeling so bad for her all alone on the island. When she made friends with the dog, I could breathe again. Their friendship touched my little 9 year old heart, and when the dog died, I sat at my desk and wept. I wasn't the only one. If I remember right, the dog died of old age, which I find more palatable than a beloved pet sacrificing itself for its owner. (A bit cliche.) Dying of old age is part of life, and Island of the Blue Dolphins is all about accepting life and doing what you have to do.