I have read with interest your breeder and breeding advice and must say. I have bred both boxers and Great Danes for many years and have experience of dogs for over 35 years and in all that time I have had fewer than a dozen litters.
Showing: I have seen that an individual judge can shape the face literally of the dog breed and have seen the demise of the classic Dane face to a cross between a Mastiff or favouring the snipe nose effect of the Dalmation. Purely on a whim, Bulldogs have been so closely bred by breeders for the show ring that they can no longer whelp naturally and instead need invasive surgery as in a C section to deliver pups. Boxer have similarly been closely breed featuring similar traits to get a smaller and more compact face.
I know the mastiff face came about in the Dane via reputable breeders who deliberately bred in the mastiff line and now we are reaping this legacy because people insist on breeding from certain breed lines.
As for the KC well they are not worth the prominence they are given I hold a KC certified pedigree for a Dane dog who is the progeny of SISTER and BROTHER union, sanctioned and certified as breeding potential. Even vetted to say his suitability for breeding purposes. Breed by a reputable- supposedly- breeder
My present Danes come from champion lines and top breeders but I deliberately Outline my breeding danes to distant lines so ensuring that any offspring is as unrelated as possible. I am fortunate to never have suffered with my dogs any established illness or breed failing or breeding fault.
I also regularly take in and rehome mistreated or neglected Danes.
I would say to anyone wishing to breed a dog, that they should ask themselves why? Why do they want to risk losing their bitch to many pregnancy, whelping and lactating problems, the dog could be ruptured if he is or his desired bitch are inexperienced, breeding a dog can change its temperament.
Once the litter arrives is there someone at home 24/7? With experience, can you afford the cost of the fees incurred such as registration, producing pedigrees(my danes come with a 6 generation pedigree over and above that of the kc provision), advertising, vets fees, food, worming, health checks. Having th bitch scanned after whelping to ensure all is well. They make a hell of a din at feeding times, are you prepared to feed them if the bitch can’t? Are you prepared to reduce your socialising a new litter in the house you won’t want strangers visiting with potential life threatening germs and infections.
Have you the room? Adequate space to exercise the puppies, at 8 weeks old they need to be out and about and can be destructive. Are you prepared to hold onto any unsuccessful sale for several weeks until you find the right level of caring home and owners with the right level of adequate knowledge.
Are you prepared to say NO to people who turn up for the puppy and slip accidentally something into conversation that makes you uneasy about handing over the puppy? Are you prepared to drive many mile to collect a returned puppy and hand over the cost you sold it for?
The fundamental underlining issue is there are no regulations to stop you from breeding your dog and nothing can prevent you from doing this BUT your conscience.