2 Chows in heat behavior

Question
I have 2 chows that are from the same parents and about a year and half part in age.  Recently the older female has begun humping the younger dog.  is this due to both being in heat?  Will having them spayed help?  What can I do?

Answer
This is dominance related behavior.  Both your dogs should have been spayed.  At this point, before spaying anyone, you need an expert evaluation of temperament by a credentialed behavior specialist (NOT a dog trainer!)  Spaying the wrong dog might escalate this situation into full blown attack, at which point you will have to rehome one of the dogs.  Locate a veterinary college nearest to your home and ask for the name and number of a Ph.D. or DVM Dog Behavior specialist.