Hi I'm new and worried/ paranoid

the instructions on the bottle are not for chickens but for dogs and cats.

i lift the feathers...make sure the bottle is set to a FINE spay, rather than a powerful squirt

Yeah I read that after the vet said it.  it makes me sad but I hope she was wrong and even if they have they are mine now I'll keep them well don't worry and as for offspring I have no cocks so fat chance ha ha   

I don't know but it does.

Things like Frontline are called systemic medicines, they are absorbed into the bird's bloodstream through the skin and then the lice bite them and eat the poison. It may not be an instant cure, but it is effective so don't despair.

And once you have it all under control treat their nest boxes and them regularly with ordinary lice powder from your farm suppliers. I dust the nesting material with lice powder every week when I change or refresh it. The girls get a good dusting under their wings and round their bums every few months, maybe three times a year.

It especially worth doing if you raise table birds as little lice scurring about when you are plucking is most unnerving!!!!

The mycoplasma is a sorry tale though. Is your vet used to poultry? Thin chance the diagnosis might not be right. Fingers crossed for you and them.