Should an ethical breeder...

Take back a pup they have bred no matter what the reason?

If not then what circumstance would you not expect them to take a dog back?

(this is not a situation I'm in.. Just to clarify)

I have always said I would take back any pup that I bred at any point in its life no matter what the reason and I stand by this- I was responsible for bringing them into the world so I will ultimately take responsibility should the need arise.

There can be many reasons why a breeder can't take a dog back at a future time, for instance, a change in health, family circumstances, financial circumstances etc.

In an ideal world, I'm sure most breeders would like to guarantee a take back - in the real world, circumstances can intervene

Ok, obviously certain circumstances/health can't be helped... But let's assume that the breeders circumstances stay the same... Surely they should take the dog back if requested?

In an ideal world, yes. However, unless they state it in there contract of sale many won't

However, on the other hand, I know of breeders that have tried endless avenues to trace one of their pups years after they were born when they hear of them being surrendered to rescue.

If a breeder indicates they will give that kind of support then unless due to health issues and unforeseen circumstances (proper reasons, not just it would be mildly inconvenient) then yes they should.

Hmmmm. What about if the dog was very DA and would put their dogs at risk?

I have always taken them back,the alternative in one particular situation would have ended up with her being pts I am sure because the bloody woman did none of the things I asked her to do, I spent months on the phone and visited to try and get her to see it was herself that was causing the problems. I had to buy her back because she was going to sell her to a 'dog whisperer' luckily my contract states that the puppy has to be returned to me, and if for any reason I am unable to take it back then it has to be homed in a mutually acceptable home. That poor girl, she was literally too scared to look at anyone, she couldn't walk through a door she bolted through it, I spent nearly a year getting her weight down to something approaching normal, (she weighed nearly 60kg)and she is now rehomed (free of charge by the way) to an absolutely smashing guy who has turned her life around.
The big breakthrough with her was when she started running through the agility tunnel at training and enjoyed it so much that she used to run through it any chance she got, I knew then that she was on the road to a happy life.
I hear all the time of breeders who are just not interested in their puppies and really cannot understand it, I love hearing from my owners about all that is happening and seeing piccies, and sometimes seeing them as well. It makes me so happy to know my babies have such excellent families and I worry myself over those who do not keep in touch.

Yes under any circumstances, there are no circumstances that a breeder should refuse, even if the dog was DA, a breeder is responsible from conception to death

In another life time when I really wanted a Mini bull terrier one of the things I liked about the breeder i was in contact with was that she had older dogs that she taken back after 8 and 9 years up for rehome ..

If I was a breeder, I would under any circumstance. I wouldn't give a refund past a certain point though.