Doxycycline side effects?

Hi there, I've got my roo (8 month old lavender orp) on 100mg of doxycycline to keep away a bacteria/virus which led me to put down my 8week old black australorp had to put her down in order so she doesn't infect everyone (if she was even infectious to begin but no one would know for sure until necropsy) so since my roo comes inside at night he has been in close(closer) contact with her so he was prescribed the meds.

He's been extra moody and irritable lately. The dr said it can cause some anemia but never mentioned any behavior things. He rarely comes after me and tries to fight (I've raised him and his other lady friends since birth so they know I am mom) but today he wouldn't let me outside without kicking and jumping on me. He also was acting the same towards the males in the house (but he's honory with them all the time ).

Does anyone have experience with doxycycline and its effects on the animals? Just trying to prepare for any consequences and know my roo is just gonna be a little crabby until the meds stop.

Thanks everyone!