I agree with the above. Test to see if the horse even needs to be dewormed.
Also. THERE IS A CORRECT TIME to deworm also. Ivermectin should be given after the first hard frost or better yet freeze. Giving it before it will be ineffective or less effective. Then again in June/July
Past those 2 times a year you need to test then rotate CLASSES not just brands. Normally for the July deworming I do not use Ivemectin but a double or triple dose of anouther products/Class.
People forget when the vaccinate and deworm that timing is just if not more important then doing it in the first place. If not done at the correct time of the year it will not work as well.
Also over doing it (deworming) is causing resistance. Iveemectin is not as effective as it once was. This is why you REALLY NEED to test to even see if you need to de worm you horse. I know I typically only deworm about 2 maybe 3 times a year.
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