Essentially what JacinLarkwell has written above. There are people tryinng to save some of these rare breeds. I know two people involved in such projects and their main concern is a) nobody knows where they are and b) that funding and publicity is kept to a small local group.
Mention a rare...
There are probably hundreds of rare breeds world wide and the best thing to esnsure they don't get spoiled by bad breeding and popularization is to not tell people about them.