ivermectin dosage

by hassan
(Egypt)

Dear Sir/ Madam, I'm a budgie breeder, i have big quaninty of full crested budgie and normal my question is about the ivermectin dosage, last year i have some symptoms like scaly face and scaly legs and i saw my birds itching their heads at perch and wire alot during the night more than day light, i used vaslin and i kept reading about these symptoms i had at that time, and i found the quick solutation for it is ivermectin i ask a vet about the ivermectin and i have it and i start using it as 1 drop at the back neck of each bird and i repeat that again after 15 days as i read, but it was hard work 2 do specially when you have many, so my question is can i use ivermectin at drinking water? and if yes,
how many days should i put at water and for how long?
can i use it at breeding season?
what is the proper measure that i should use at water?
many thanks
faithfully yours
hassan