Grief over the loss of a pet dog can be so deep and long-lasting. You can feel your heart really breaking, the tears flowing, and a painful emptiness haunting you as you move around the house—as you live another day in unfamiliar but stabbing pain.

You may try to drown your heartache by taking a long nap. Your appetite feels gone, and you are not in the mood for physical activities most of the time.

There are occasions, too, that you turn to emotional eating or other bad habits when the guilt, unhappiness, and all other negative emotions assail you simultaneously. And for some dog owners, even though death is natural for all living things, they silently blame themselves for the demise of their pet dog.

Amid all these sorrows, make sure you take at least a few moments to check how the loss of one of your beloved dogs is affecting its surviving companion or companions.

There’s a new study that shows dogs grieve too when they lose a companion dog. Especially if the two had been close, sharing food and toys, playing, or sleeping together.

After the death of a companion, dogs may howl or be noisier than usual, eat less, play less, and/or sleep more. They may also become more fearful and more demanding of your attention. And this behavior may last almost a year in some cases.

The team of Federica Pirrone, who conducted the study at the University of Milan, Italy, likens a dog’s mind to that of a two-year-old toddler. Pirrone says these behaviors indicate mourning.

“It could be indicative of suffering. Separation from a companion could be expected to cause behavioral changes, which certainly overlap those behaviors that we normally interpret as being grief and mourning.”

The study also indicates that the reaction of the human owner may affect the degree of grief that the dog feels. When the human owner feels more intense pain or anger, the dog becomes more anxious and fearful.

During this difficult time, the dog longs for human attention, for warmth and reassurance of love.

In fact, a dog who has been left behind feels lonelier over the passing away of its companion dog than it will over its own death, since dogs don’t appear to have much capacity to contemplate their own demise.

And so, should you ever find yourself mourning over the loss of a pet dog, take the time to check on your other dog(s). Hug it, find solace in each other’s warmth, weep together, and begin living each day still feeling lonely but not alone.

In time, the heartache you both share will fade away, and you can start all over again.