This horse was originally marked as "Horse" for sex, the other parent in the bloodline was marked as a colt. As it stands, it says my mare has two grandsires that produced "Dell Mix" with no mare on that part of the tree (see: https://www.allbreedpedigree.com/dell+mix )
After digging around, I think Royal Dell Bug being marked as a colt is less ambiguous than Docs Mixture being marked as "horse" and deduced this was a dam rather than a sire. If you're reading this and can confirm Docs Mixture is a mare or a stallion, then Royal Dell Bug will need updated instead.