The instant you brought that tiny fur ball home from the shelter, your dog became a fixture in your son’s life—his best friend while you’ve been at the office. But illness caused her to be put to sleep. You’ve tried to explain why his pal is no longer there, but your child is sad and confused—and your heart is aching, too. The death of a pet is often a child’s  first experience with the loss of a loved one, an important step in his emotional development.

As much as you want to shelter him from the grief, your role here is to help him to cope, to understand his feelings and to let him express himself so he can work through this difficult time and ultimately deal with other losses. While an explanation like “Coco lived a good life, but now she has died and left us” is fine, understand that preschoolers don’t perceive death as permanent, says Diane Cantrell, a licensed professional counselor and author of Good-bye, Baby Max.

So your child may wonder where his pet is and who’s watching and feeding her while she’s away. Let your cultural and spiritual beliefs guide your answers as you assure him the pet is at peace and not in pain. Try asking him where he thinks the dog has gone to help shape your talk. This loss may cause your child to become unusually clingy when you leave for work, so assure him that although his pet won’t return, you will. He might also imagine that something he thought or did caused his pet’s death, so discuss what he thinks about why the dog died. “Be sure to reassure him that it wasn’t his fault and that there are some things, like death, that we can’t control,” says Susan McGroarty, PhD, a clinical psychologist and assistant professor at Chestnut Hill College in Philadelphia. As you comfort your child, don’t overlook your own bereavement. He’ll feel your grief, so let him know that sadness is a normal part of life for kids and grown-ups. Yet even as you validate feelings, encourage his resilience so he doesn’t get stuck in hopelessness. Say something simple like “I know this feels bad right now, but I know you’ll be okay.” Draw his attention to animals he’s observed in nature to remind him that life goes on. Don’t try to conceal the pet’s death; this may heighten his anxiety because he’ll sense you’re trying to hide something. Help him heal by suggesting activities like making a photo collage of his pet or planting flowers or a tree to commemorate her life. If possible, include other children. These are good ways to ease sadness and remind him that though he’s lost a friend, there’s still a lot of life for him to share in.

For extra comfort listen to your child’s words and how he says them. Is he moody and irritable? Let him know that it’s okay to feel the way he does and that others feel that way sometimes, too.

Watch him play. If it seems he’s feeling bad—fighting with siblings or pouting—redirect his attention to an activity he enjoys, like going to the park or baking cookies.

Engage with him to help him overcome sadness. Ask about his happiest times with the dog and have him draw a picture or tell a story about them. Encourage him, but let him guide the activity.