My baby chicks are dying!

[crayonartist]

I recently hatched out 25 chicks from my mixed flock and today when I was closing up my barn and checking on my chicks two were dead and a third is in bad shape. The odd thing is, its only my barred rock crosses that are getting sick. Conditions are sanitary, no new foods have been introduced, there is plenty of water (which is medicated) along with medicated feed, they have ample space, my heat hasn't fluctuated drastically, I haven't introduced any new birds to my older flock, and my chicks are kept separate from the older flock. I don't know what is happening. There are no signs of trauma. The one that is currently not doing well seems lethargic and is having trouble balancing. My chicks are now 3 weeks old and have been healthy happy little birds up until now. If anyone has an advise I would greatly appreciate it! Thank you!

 

[curious chickee]

Might be vitamin deficient try adding vit/ electrolytes to their water. By ample space you mean they can get to a cooler spot away from the heat.