Invermectin Pour-On | UFA Co-operative Ltd.

Invermectin Pour-On

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Best Practices Lead to Best Results

Ivermectin Pour-On for Cattle is a unique chemical entity. Its convenience, broad-spectrum efficacy and wide safety margin make it an excellent antiparasitic product of choice for cattle. In fact, one dose will effectively control a wide range of costly internal and external parasites, including sucking and biting lice, warbles, sarcoptic mange mites, flies and gastrointestinal roundworms. Because these parasites can greatly impair the health and productivity of your cattle, proper management and best practices of the pour-on are critical to ensuring best results.

“There is a fallacy regarding the performance of pour-on antiparasitic products in the field,” says Dr. Merle Olson, founder & vice-president research and development of Solvet. “Often, it’s not resistance at all, but a misinterpretation of efficacy of the active agent ivermectin and common errors with application and management.”

Olson says that Ivermectin Pour-On is very effective in controlling the adult and larva stages of roundworms like Ostertagia ostertagi. It kills Osteragia ostertagi with no resistance.

“These roundworm parasites have the most impact on beef cattle growth,” says Olson. “In fact, most of the performance issues that we see from the parasite load in cattle, including depressed weight gains, poor feed efficiency, diarrhea in calves and a reduction of milk production and reproductive inefficiency in cows, come from ostertagia. That is why proper management and application of the product to ensure its effectiveness on roundworms is so important.”

To ensure the performance of your Ivermectin Pour-On this fall, Dr. Olson recommends the following:

Be Aware of Product Efficacy and Treat Every Animal

“Ivermectin Pour-On is effective for 90 days from the date of treatment. After 90 days, product activation is gone from the system. If you introduce new animals or forget to treat just one animal, the whole herd can get re-infected after three months.”

“Ivermectin Pour-On is effective for 49 days against lice from the date of treatment. After 49 days, product activation is gone from the system. Before introducing any new animals to your herd, they should be treated and quarantined for 4 days prior to.”

Proper Application

“To support efficacy, animals should not be treated in extreme cold. Ivermectin Pour-On should be applied when temperatures are above 0° C. When it is very cold, the product may not be as effective as the animal’s peripheral circulation is decreased because their body conserves heat and the ivermectin is not as readily absorbed through the skin.”

“Be attentive to how you store your product. Make sure it is nice and warm when you use it and keep your pour-on warm while you are processing your cattle. Use a heat pack if needed and don’t leave the pour-on in the truck all night long in -30° C weather.”

Consideration When Treating Lice in the Fall

“It is important to remember that maximum lice occurrence actually occurs in January and February. Those are the months that we see the most lice on the animals. If you treat animals in October, you will be missing their peak season. Therefore, I recommend retreating in January or February when temperatures are conducive to application.”

“Ivermectin Pour-On is extremely cost effective and provides very good return on investment, even if you need to reapply over the winter on cattle placed late summer or early fall.”

Often producers will assume that just because a cow is itching that it has lice and that their pour-on is not effective or that there may be resistance issues. This is generally not the case. In fact, 95 per cent of the treated cattle that are scratching do not have lice. Although we don’t always know the causes, it could be attributed to frostbite, allergies or irritation from barley or straw hulls. Some of the most heavily louse-infected cattle will have a normal hair coat.”


For over 20 years, UFA has supported the cattle industry by delivering the tools, products, services and support for successful business. To learn more about our products, please visit your local UFA or connect with one of our Livestock Specialists by calling 1-877-258-4500, Option 1 or view our Livestock Specialists contact information.