Breeding dogs from the same parents but different litters is not something that is recommended, especially if you are new to breeding and not very knowledgeable about genetics and how breeding closely related dogs may impact the puppies produced. Even experienced breeders who breed closely related dogs stumble on problems, because every time you breed closely related dogs, you increase the risks for undesirable traits to pop up. Following is information about why you don't want to breed dogs from the same parents but different litters.
Can You Breed Dogs From the Same Parents But Different Litters?
Yes, you can, but it is not recommended. Technically, when you breed dogs from the same parents but different litters, to put it bluntly, you are literally breeding brothers and sisters.
When you breed closely related dogs such as mother and dad, brother and sisters, dads and daughters and mothers and sons, and so forth, you are inbreeding. While inbreeding is something that professional breeders sometimes do, it is not a very safe practice.
The purpose of inbreeding is to hopefully combine all the good characteristics from brother and sister into one puppy. In other words, the goal is to fix exceptional dog traits in the subsequent puppies. However, there is also risk that negative characteristics from hidden recessive genes may pop up leading to smaller litter size. lowered immune systems and unhealthy puppies. This happens because, when breeding closely related dogs, you have less genetic diversity.
Historically, inbreeding was a common practice among several royal families in Europe of the 18th century. The purpose was to maintain the royal blood pure. Not surprisingly, countless royals developed high incidences of inherited diseases including bleeding disorders, mental illnesses and cancer. What's more, in most cases, the inbreeding of royal families more often than not, entailed marriages between cousins rather than sisters to brothers.
In the hands of inexperienced breeders, there are therefore considerable risks that, instead of doubling up good characteristics, the "poor" traits will be doubled up, leading to significant problems, not only to the affected dogs but also to the owners, who will face the heartaches associated with seeing their dogs get ill along with the financial aspect of treating the affected dogs.
What To Do?
As seen, inbreeding leads to significant problems because you are dealing with a high concentration of the same genetic material being passed to the offspring. The risks at stake may be too high.
If you are seriously considering inbreeding, consult with a knowledgeable breeder who is willing to be your mentor. Generally, before considering this practice, you should carefully look back into at least three or more generations and determine whether there is any history of health problems or undesirable traits.
Inbreeding should therefore only be done if the breeder can ascertain that both dogs are entirely really healthy, are perfect (or close to perfect examples( of the breed, and have no history of carrying recessive (hidden) traits across several generations. Only then, can inbreeding be considered, keeping in mind though that even in their experts hands, there may risks at stake.
If you do not have any mentor, but are determined to breed, it might be therefore safer to breed two healthy, yet unrelated dogs rather than potentially creating litters of puppies with breed faults, weakened immune and a host of other potential health problems.