[gemy]

I am not sure which articles you read - but one problem as minimally mentioned above is that the littermates will tend to continue to bond with each other and not so much their humans. This can make training difficult and also separation anxiety from each other more prevalent. As noted above there are things you can do to minimize this.

The only other problem that might rear its head are health issues. Those health issues that often are duplicated throughout the litter; things like LP and LCP, digestive issues and or allergy issues - along with eyes - liver issues etc.