Brindle is DOMINANT, cannot be carried as recessive
can act with piebald on the same dog. A brindled piebald will show brindling in the colored areas, not the white areas.
 

Red Brindle Smooth Piebald
(mother is a black & tan piebald and daddy is a red brindle)
"Stowe's Texas Trooper MSP"
Photo from: Texas Tail Wagger's