but wouldn't show breeders want to buy each others' puppies from time to time to keep the breed line gene pool fresh? (I don't know how it works)
I’m preface this by saying I don’t agree with the Kennel club and everything they stand for so I’m perhaps not the best person to ask but here goes...
Yes, breeders do buy other breeders dogs.
But this isn’t always a good thing.
The Kennel Club breed standards mean breeders strive to create dogs with a very set and specific ‘look’.
This invites inbreeding as when a breeder gets a particularly good dog that fits closely with the standards and wins lots of medals not only do they tend to use that dog for breeding for themselves but other breeders want the genetics of that dog in their breeding lines too in the hope they will breed the next winner so the dog is either put to stud where it can father many hundreds of litters in some cases or the other breeders buy puppies of that top winning bitch to breed themselves.
Also, close inbreeding can ‘fix’ particularly desirable (and undesirable) traits into the line.
I’ve often seen ‘close line bred’ pedigree show dog litters advertised.
In a lot of breeds, the rate of inbreeding is often quite high, imo, because of ‘line breeding’ and because of using one top winning show dog to stud and father hundreds of puppies and because of the tendency of breeders to buy new dogs from kennels that have proven very successful in the ring.
Often, if you look at the pedigrees of show dogs from a successful show kennels, you often find the same few kennel names in the pedigrees.
The one good thing about Kennel Club registration is you can use it to check whether the parents of your puppy were related (you want as low an inbreeding rate as possible) but as far as I am concerned that is where the benefits of the Kennel Club end.
They are no guarantee of a good breeder. No guarantee at all.
A ‘top show winning kennel’ for me, would be a disadvantage, not an advantage.
Because I would assume a show kennel will have a large volume of dogs, I wouldn’t be surprised if their puppies had high COI and I would worry that a show kennel may be prioritising a show winning ‘look’ over good health song temperament