Aggressive fighting between littermates beginning at 8 weeks - is this common ?

I am an ethologist who has studied wild canids and trained dogs but these pups are putting all I know to the test.

My husband and I found ourselves raising a litter of 7. Very long story short we have both parents, mutts rescued from Mexico. The mom is shepherd and some sight hound, dad is greyhound plus mystery dog.

It is taking longer to find their forever homes so we still have four 13 week old pups. At just 8 weeks old they started fighting. We have lots of space and they get lots of exercise and stimuli inside and out, that wasn’t the problem. The fights were infrequent but serious, amazingly they never broke each other’s skin. Yet. Incidentally both parents are sweet and not “dominant” or “aggressive”, though the mom is not keen on other people or dogs.


To complicate things my husband is determined to keep 2 if not 3, but I do 90% of the training, exercising, and we have 3 other dogs already. I am very concerned what all these doggy relationships will be as they all age. Right now all the pups are good with parents, who are teaching them to play but not to be obnoxious.

What are the odds fighting will get worse even if socialized? we live in a rural place, I have to work it to get them exposed to other people and dog savvy dogs, not happening much during a pandemic. What if they decide to compete with mom or dad or each other as they get bigger, despite constant training?

thanks in advance for your experiences.

Below is a pic of mom and one 13 week old brindle girl, they are getting BIG. And little white Samadhi. Five white pups out of 7 from two black parents!