Marilyn Pernatin never had a pet until five years ago when she got her dog, Shana. She came to love being greeted at the door by Shana after coming home from running errands or seeing friends.

When Shana died last month, Pernatin was devastated. She was so eager for comfort that she and her husband drove from their home in Silver Spring to Fairfax city one night for the monthly meeting of a sup0port group for people whose pets are dying or have died. For an hour and a half, she and 17 others talked about their grief.

"I learned a lot from the meeting," Pernatin said. "I knew that I wasn't by myself . . . You really feel you're not alone. It's really all right to grieve."

In these days of self-help organizations for everyone from would-be dieters to people hoping to improve their love lives, it is not surprising that a group should spring up for bereaved pet owners in a nation where an estimated 42 percent of the population has a pet and millions of dollars are spent on food, trinkets and interment.

The pet grief group is sponsored by the Fairfax County Department of Animal Control, whose spokesman, Carol Taylor, said it is believe dto be the only one of its kind in the area. Taylor said the sessions of the group will continue through May on a trial basis, and officials will then decide whether there is enough demand to continue them.

Reaction has been good, she said, with the exception of two callers who derided the idea of county sponsorship. Taylor said the expense for the program is minimal because the meetings are held in apublic building and the counselors are volunteers.

Grieving over a dead pet generally follows the same sequence of psychological stages (denial to anger to depression to acceptance) as reaction to the death of a close friend or relative, according to social worker Kathy Reiter and psychologist Marcy Alvo, the group's volunteer counselors.

"The more emotion you invested in your pet, the more loneliness or anxiety you may be feeling," Reiter told the nine people who attended the group's meeting last week.

They included a couple who mourned the death of their sick dog and felt guilt about having had to put him to sleep, four bereaved cat owners, and a man agonizing over when and how to put his terminally ill dog to sleep. Several people cried. Others were so filled with sadness they could barely speak.

Those involved with the group say they know that some people will ridicule the idea that a person could feel such deep grief for an animal. That is one reason, they say, why group therapy is needed: Mourning for a person's death is permitted, but society offers only slight solace to those who have lost an animal friend.

"The first one that says, 'It's just a cat,' I'm going to flatten them," said Marge Ireland, a Falls Church resident who came to the January meeting after the death of her pet, Poo. "They're one of the family, really."

"They have lost an animal," Reiter said of her clients, "but in some respects they have lost someone who has been closer to them than any human ever will be."

Reiter said most people who come to the monthly meetings, which began in November, are suffering from the los of dogs or cats, although she has seen people in her private practice who are saddened by the death of "everything from ferrets to turtles. people even get attached to their fish."

It was the death in January of their 7 1/2-year-oldf pet rabbit, Muffin, that borught Sally and Lary Capots of annandale to the Fairfax City Regional Library, where the group meets on the third Wednesday of every month. Similar groups for children are held on the third Saturday of each month.

"Some people are willing to listen right after it, but after a few weeks they figure you're back to your normal life," Sally Capots said. "You need an outlet. That is why the group is so good."

She still chokes up with emotion when she describes Muffin's habits, such as the way he reared up on his hind legs every morning to beg for his carrot breakfast or gently nuzzled his head under her hand when he wanted to be petted.

"A lot of people don't understand about rabbits beause they picture them outside in a hutch sitting around and looking cute," she said. "They're really like cats and dogs. They really have their own routine."

The Capotses are hoping to assuage some of their grief by having two oil paintings made of Muffin, but Sally Capots doubts she will look for a new pet. "I'm not in a hurry to get another animal because I know what I went through with this one," she said."

Pernatin, though, has found a new dog, a white poodle adopted from the county animal shelter.

"We know it would not bring back our original pet," she said of her plans to adopt a new pet, "but it would be a transfer of love. It's like doing a good deed."