If you are not moving your animals, it might be a good idea to let the
new owners know there is a cemetery.  I work for a real estate attorney
and there was an incident a few years ago in which the new owners were
tilling a garden and discovered a tiny coffin.  It was thought that it
was a baby but it turned out to be a much loved cat.  Now there is a new
law here (Iowa) that if you transfer property you have to let the new
owners know if there is a burial site on the property.
[Posted in FML issue 3730]