I have these. I think that's easy to pull it. The rooster will have red in their back. Ben's develop a large floppy comb pretty young. They do act like typical leghorns. These are bread from the brown Leghorn and the blue Andalusian. I get that it's hard to determine when you don't have both...
I used to mistakenly believe they got all their chicks from Hoover. They get chicks from everywhere. In my area they get quite a few from Privet in New Mexico
Judy what this drug does you are recommending prevents the coccidiosis from absorbing the B1. That's what coccidiosis does it steals the B1 or thiamine from the chicken causing deficiencies. It makes great sense to make sure your birds have a adequate supply of B1 to prevent deficiencies.