Dog will not eat or drink, seems too weak

You don't give us much to go on, your information is too sketchy. Why do you think we could tell you anything without knowing the kind of dog and the age of your dog? We can't diagnose on the internet anyway, but we can give you some insight but my guess is, take your dog to the vet.

If your dog is weak and not moving.. than I would suggest to take it into the vet for a check-up. And if this is severe enough I would suggest to pay for the emergency fee, unless you want your dog to die..