My dogs have been on Trifexus, seemed to always have good results with no issues. I hate to even change but it is kinda expensive. Guess my question is that Is using ivomec just as effective as anything out there? I here alot of kennels use this. Also if you do agree what about flea prevention? If i would have to buy a flea prevention would the ivomec and advantage ( pick one ) cost as much as the Trifexus? Think im paying about 190.00 for one dog every 6 months. Looking for suggestions.