When puppies or kittens reach four months and they still don't have permanent homes, breeders now have more work to raise proper teenage puppies and kittens. And then you have the additional stress of not being able to find owners that will meet your expectations.
Finally, after all puppies and kittens have left for their respective homes, breeders dive back into the family, work and their adult dogs trying to compensate for the lost time. This vicious circle goes on and on, from litter to litter. Gradually, you acuumulate the burnout. From the intention to fulfill an interesting mating to the fear that part of the litter will stay with you forever or will just wait for too long. This running in circles leads to the inevitable thought – maybe, I should close my kennel or cattery? Why do I even need all this when, instead of being a breeder, I am turning into a seller who is desperately trying to show the value of my puppies or kittens to a random person? And then apathy comes.