It may be a sign of our times that grief theory--stages of mourning, etc.--has now filtered down to denial and despair at the demise of Rover or Tabby. To be fair, there are many whose lives are brightened less by human companionship than by the company of a pet. But Nieburg, a bereavement therapist who counsels veterinarians on handling the grief-stricken survivors, probably goes too far in assuring us that mourning and guilt under the circumstances of pet death are quite commonplace. Cases and letters present us with pictures of pet owners who can't forgive themselves for not jumping up to let the dog in immediately when he scratched--with the result that he was run over by a car. Some sections are more applicable: helping children cope after they lose the one ""friend"" who accepted them unconditionally (support and understanding are the key); acceptable and unacceptable methods of euthanasia; whether to take the plunge with another pet (it depends largely on the individual, but make sure your mourning for the first pet has been completed). Much of this, however, will register only with fervent pet-fanciers.