It's an issue almost every pet owner confronts at some time: How do you know when it's time to have your animal euthanized?

"There isn't one factor that's going to stand out and say, 'Hey it's time,'" says Kim Intino, director of shelter services for The Humane Society of the United States.

When an animal's behavior changes — it's not eating, sleeping comfortably, grooming itself or moving around, can't eliminate or has no interest in playing — the time may be near.

"It cannot tell us, I'm in a lot of pain," Intino says. "If we assess that, then we have to not worry about our own feelings that we are going to miss the pet — of course we are — but (think about) things to be doing for the pet, making those decisions in the best interests of the pet."

Other steps along the way:

Discuss it with the family. It should be a family decision, a consensus that Spots isn't who he used to be and is not enjoying life. Also consult friends or someone in the animal welfare business.

Assess the pet's prognosis. Are its struggles just part of growing old, something that can be tolerated because a cure or help is available? Will the animal get better? Or is there nothing that can be done, and are you just prolonging the pet's suffering? Reason it out.

"It's one of the most difficult but necessary decisions we have to make," Intino says, "and we have to make it, as much as we can, from an unselfish standpoint."

Talk to your vet, who knows your pet and can help determine if the time is now. The vet can also answer questions about the euthanasia process. If you don't have a vet, or if you want another opinion, check with your local animal shelter.

"Speaking to a euthanasia technician who understands the process would be very helpful, to explain the actual procedure," Intino says. "The person who picks up the phone (at the shelter) probably is not the best person to talk to."

When the time comes, be in the room if you can. The closure will help. "When (the pet owner) sees it's such a peaceful process," Intino says, "and they're there to see the pet go to the other side, I think it's a very rewarding experience."

In the end it's an important part of pet ownership.

"When it comes down to it, being able to say you did everything you could and you acted in the best interests of the animal is going to be that last part of you being a wonderful pet owner," she says. "You gave that pet a wonderful life, and it also may come down to you giving that pet a wonderful death when it's time."

Dealing with guilt

Guilt is an unfortunate byproduct after a pet has been euthanized. "It is human nature to judge ourselves harshly and see only the times we failed — real or not — instead of the lifetime of goodness we have provided our pet," says Dr. Janet Tobiassen Crosby, the veterinarian "on call" at about.com. "Try to redirect the feelings of inadequacy or 'wrongdoing' to the times that you shared with your pet in good health (and) the times that you provided for ... and took great care of your pet."

Her column, "The Twilight Time," on the site addresses a variety of related issues.

About the process

Euthanasia usually is accomplished for pets by injection of a death-inducing drug, notes the American Veterinary Medical Association on its Web site, avma.org. The veterinarian may administer a tranquilizer first to relax your pet. Following injection of the euthanasia drug, your pet will immediately become deeply and irreversibly unconscious. Death will be quick and painless.

Distributed by McClatchy-Tribune Information Services.