my little sebright hen, from time to time has a little bit of white foam in the corner of her eye. not alot but from time to time she does. ive had chickens with coryza before but this doesnt seem like it to me. doesnt stink, no discharge from her nose, just from time to time has a little foamy substance in her eye. its not there now, but i saw it about 2 weeks ago and then it wasnt there the next day. hmmm, what could it be?