As a new "aspiring" breeder I believe we should discuss, explain and educate the people we sell our dogs to as to why it would not be healthy to breed certain dogs. Contracts are great, but people do not always follow them...I believe that we should use our knowledge to decide who would be suitable to breed. I think to spay/neuter before the puppies leave our homes is a great idea but not always an option.
The problem is alot of larger dogs are easy to breed and with these little ones, (especially with the TREND being "the smaler, the better") there are alot of people breeding out of standard and they don't know the dangers of breeding these small dogs.
I don't know...it should be up to the discretion of the breeder, within reason...