It's selfish to leave your pet to fend for itself.
John is on a weeklong vacation but has only hired someone to look after his dog for a week.
John wants to enjoy his vacation a little longer.
John calls the dog-watcher and asks him to look after his dog a few more days.
John stays a few days extra on his vacation and doesn't notify the dog-watcher.
John's dog is happy and healthy.
John's dog becomes anxious and hungry and gets sick.