Presuming they're getting good grower feed and grit with minimal treats, could there be something environmental going on there? What you used for cleaning perhaps or some other thing like paint, varnish, or other chemical that could be causing it?Good morning. I have a 24 week old barnevelder (not yet laying) who has a significant head tremor this morning. I noticed a head twitch a couple weeks ago, and thought it was related to the noise of having a couple trees removed. Yesterday, we had our ceiling cleaned (also noisy) and the twitch has turned into a tremor this morning. We just completed a round of wormer (AquaSol), but the twitch had started prior to the wormer. She has been eating and her poop appears normal. This morning, she did not come out of the hen house with the rest of the flock (who are not showing any head twitching), and is sitting on the roost. No signs of mites or lice, but will look closer. No scratching at ear/head. I will be isolating her this morning. She has always been a little more flighty than the others. Attached video from this morning. Any ideas would be hugely appreciated.
If not, I've had a silkie (prone to vitamin deficiencies) that acted much like your first video, but not quite so fast of head tremors, more like looking left and shaking, then looking right and shaking, then just darts off a few feet. This started Day 1. I did E and Selenium then Nutra Drench in water once a week, to this day. She's now nearing 6 months old, and still does it, no better, no worse. Yours seems much worse though is why I think it's something environmental if you've already given the supplements and there's not much change.