the fly control is a nice benefit of the pour-on isnt it?
we used pour-on for years. it sure was convenient. i could even worm most cows out in the pasture if i needed to. lately it doesnt seem to work as well, i didnt konw if our worms were building up a resitance to it or what (i imagine it would work better in heavier than recommended doses). my vet says the thing about the pour-on is that different cows absorb it differently, depending on their hide and such (and obviously really hairy cows are a little trickier to get it on good-). also you have to ensure it stays on for a certain amount of time before it rains or the waterbuffalo get submerged in the pond.
i imagine you could probably get away with skipping the ivomec-plus every other year unless you are just really ate up with liverflukes. this would save a few dollars.
we used mostly the ivomec pour-on for years and i had about decided the ivomec wasnt effective anymore. but then when i got goats goat farmers were telling me that most all goat people worm orally now. they claim that the oral is more effective, faster than the injectible but also leaves the body sooner whereas the injectible lasts longer but is distributed throughout and is therefor less concentrated (for lack of better wording). the drawback is that massive worm dieout from worming orally (or any way if you worm hard enough i suppose) is that there can be internal bleeding where the worms were.
having said that, i have started worming my cows orally with ivomec injectible. i just put it in their feed whenever i see one that needs worming. and it has worked really well, better than actually injecting the injectible i think. so i've ruled out resistance. not sure if its due to the wormer going directly to the worms and the stomach or what, but it works. i usually see drastic results in 1-2 weeks.
*edit to say* ive heard you need to give more injectible than recommended on the bottle if you are going to give it orally but i havent found this to be the case. i put whatever the bottle recommends to be given as an injectible in a syringe and just squirt that on the feed and it has worked well for me. so i wont increase the dosage until it seems there is a need to.
