I am a stay at home Mom with a 3-year-old son who started pre-school two months ago. He never had separation anxiety in his infancy or from the start of school. For the last month he has cried every time I drop him off at school. It seems to be getting worse. He is now starting to cry at home if I leave at all or if he is with a baby sitter or his Daddy.We had to put my 14 year old dog down about the time his crying started. He wasn't that attached to her but it may be hard for him to understand. I told him she was very sore and old. She was hurting and was needing to go to sleep and that she wouldn't hurt anymore. He told her goodnight. Occasionally he asks me where she is and I say remember she went to sleep. It's a hard one, they are little enough and big enough that they know something's up and yet it is a tough one to discuss. I wonder if this is what is causing the shift in any and all separations from him.Yes, unfortunately it's quite likely that the loss of the dog is at the bottom of the problem, along with your attempt at explaining it. I know it's hard for us parents to find words in situations like this. It's important to put ourselves in our children's places and imagine what both the experience and the words mean to them. Our special words about death, such as "going to sleep," can be very confusing to a child.Imagine you are three years old. All your life your family has included mommy, daddy, and the dog, as well as you. You probably don't think of the dog as any less of a family member than anyone else. Suddenly one day she is taken away in the car and never comes back (or disappears mysteriously while you are at school). When you ask your mommy about it, she says that the family member who disappeared was very sore and old. Well, you know that you are young, and your baby brother is young, but your mommy and daddy are old, aren't they? They may be even older than the dog. If the dog was taken away because she was old, maybe it could happen to your mommy. Your mommy also says that the dog was hurting and needed to go to sleep. But everyone goes to sleep every night, don't they? If the dog's asleep, why isn't she in her bed? If she's sleeping somewhere else, why doesn't she come back? What if someone else is hurt or sore? Will they also go to sleep somewhere else and not come back? You need your mommy a lot, and you don't want to risk being separated from her in case she gets hurt or sore and needs this kind of sleep in some place where you can't find her. What if she disappears or "goes to sleep" too? You need to watch her all the time to make sure that it doesn't happen.So back in your own skin : Bring up the subject of the dog with your son directly, and ask him if he's worried about what happened to her. He needs responses to all the things he may be worried about. First of all, tell him that she isn't asleep, she's dead. What you say to him about death depends on what you believe. If you believe in an afterlife, tell him that her body was very sick and worn out, so she needed to leave it behind and go somewhere where she wouldn't be in that sick hurting body any more. If you don't believe in an afterlife, tell him that she had come to the end of the time when dogs can stay alive in this world. Explain that dogs only live about 12 to 14 years, but humans usually live much longer, at least 70 or 80 years, and that you are in good health. You are grownup but you aren't old, so he doesn't have to worry about you dying. You won't die until he's older than you are now. Encourage him to tell you everything he's worried about, and answer all your son's questions with the truth, told as simply as possible. I think you'll find that this resolves the problem. You may also want to ask your children's librarian for books for preschoolers about animals dying.