Also, as Sidge says, you might find she's not that upset. We had to tell DD (5) about one of her 3 goldfish dying. I was quite worried she'd be really upset but instead she just asked "I wonder which one will die next?"

I got this when DD was 3 and we found one of our doves with its head bitten off (CAT!!!!) so I tried to bury it on the QT, of course she spotted it...

In the end it was agreed that:
Everything in the world lives a certain time then dies.
Dying is like falling asleep but you never wake up
If your head is removed you will die
Our cat did not bite the head off as our dove as our cat is too nice (oh the innocence of youth!)
When you die you are buried in the ground
Being in the ground means you rejoin the cycle of life
Dead things go away for ever and we never se them again, that is why we have memories and photos
It is sad when things we love, die
Mummy and daddy will not die for years and years as people live a lot longer than doves.
Cue a LOT of questions about "how long until X/Y/Z dies?" which was a bit upsetting as she asked when my cat would die, then the grand parents etc. Deal with it as facts.
She did not get upset, she saw it as factual

Endpiece: when, age 4, she was taught about Easter and the crucifixion and the ressurection she came home and said "Jesus came back from the dead!" Pause. "He's the only one who has ever done that, isn't he? No one else can do that." Pause. "But Jesus has gone away though, as he is with his Daddy now."
So they do take it in.

Obviously she needs to know she won't be able to see the dog anymore. I know this may sound obvious but she might not realise that. She won't understand what death means but she will understand that the dog has gone, if you see what I mean. I would be prepared for questions about where the dog is now if I were you. And I would also make sure there's something special planned for her to do at granny's house to take her mind off the lack of dog until she gets used to the situation.

I think at that age less can be more in terms of information - keep it very simple; Granny's dog was so old his body couldn't work any more and so it has died. Dead is when dogs/people can't do anything any more (as Tinkjon said).

Don't be afraid to use the words dead, death, died etc. Euphemisms such as passed on, gone to sleep, in heaven etc can be confusing for young children and they don't understand them. Gone to sleep could imply that the dog/person may wake up, and can cause a fear of the child itself going to sleep and not waking.

You may find when you tell her she just says "oh ok" and runs off to play. It can take time for it to sink in and may not do so until she sees that the dog is no longer at their house.

I did a bit of research about this some time ago and apparently the best way to explain death is as the absence of familiar life functions. So if it's a dog, you say that it means they can't run, bark, chase balls etc. or if it's a person you say they can't walk, talk, etc. Don't say they've gone to sleep, or your dd could get frightened about going to sleep. Also try to avoid saying it was because they were ill because the child might then worry about minor illnesses. HTH, sorry to hear about your aunt.

snickersnacks, we just put it plainly with our kids when the hamster died... i.e. it has gotten very old and tired and went into a long sleep from which he won't wake up. Worked to a certain degree. DD (then 5) then of course deduced that myself and dh would die soon as we're sooo old (charming...). We assured her that we'll be around for a long time and everything was fine.

My mother has just rung to say that their dog has died - they'd had him for years and he was a huge favourite with dd. It was the highlight of going to visit granny and grandpa, and she spends the whole journey talking about playing with the dog.

We're visiting this weekend and I want to explain to her what has happened, but don't really know where to start - neither dh nor I are religious, so I can't use the "he's in heaven looking down" approach. How do you explain the concept of death to a small child? I'm thinking this might be a good time to explain it as clearly as possible, as one of my aunts is very ill and there's going to be a point where the issue of her death is going to have to be explained to dd as well .