Loss is inevitable. There are many different types of loss.
Maybe it was a marriage that ended in divorce, or one that simply drifted apart; or maybe it was an old high school relationship that held significance in your heart. Even short-term romances can leave a broken heart causing one grief and inability to move forward.
Did you know that changes in one's life can create a loss, even if that change is positive? A job promotion, marriage, graduation or even moving to a new place can create grief from the changes in one's new routine.
Pets get to live alongside us experiencing much of our day-to-day lifestyle. The sudden absence of a close companion, though not human, can certainly cause substantial grief, even years past.