you can get ivermec from a farmers supplier.
it is injected and the dose is 1ml for every 25kg in weight.
you give the dog a shot and another shot a week later.
you give the dog the shot in the scruff of the neck and it does burn a bit so a good rub of the neck area after the dose is givin.
it kills flea,s,ticks,treats mange and certain type of worm but not ring worm,so you will have to get the normal worm dose for the dog also.