Brand: IVOMEC ® 1% injection


FORMULATION: «injectable» to be administered subcutaneously under the loose skin in front of, or behind, the shoulder in cattle; in the neck in sheep; immediately behind the ear in swine.

ACTIVE INGREDIENT(S): ivermectin: 10 mg/mL (=1.0%)

CHEMICAL CLASS of the active ingredient(s): macrocyclic lactone


CATTLE, SHEEP, SWINE (cattle everywhere; sheep & swine depending on the country; in some countries also minor species such as goats, reindeer, bison, etc.)

PARASITES CONTROLLED* (spectrum of activity)

* Country-specific differences may apply: read the product label.





*Can be slightly different in some countries: read the product label!

  • Cattle: 200 mcg/kg bw, equivalent to 1 ml/50 kg (=110 lb) bw
  • Sheep: 200 mcg/kg bw, equivalent to 0.5 ml/25 kg (=55 lb) bw
  • Swine: 300 mcg/kg bw, equivalent to 1 ml/33 kg (=75 lb) bw


  • LD50 (acute oral) in rats: 5000 mg/kg (estimate, source: MSDS)
  • LD50 (acute dermal) in rats: >66000 mg/kg (estimate, source: MSDS)
  • Estimated hazard class according to the WHO: not applicable for veterinary medicines

Suspected poisoning? Read the articles on ivermectin safety in this site.

Withholding periods (=withdrawal times) for meat & milk (country-specific differences may apply: read the product label)

  • Cattle: USA, Canada: 35 days (CA); UK: 49 days; Australia: 28 days.
  • Sheep: Canada: 35 days; UK: 42 days
  • Swine: USA, Canada: 18 days: UK: 28 days

Not approved for use on dairy animals producing milk for human consumption.

Non-lactating dairy cattle: treat at least 2 months prior to calving.

WARNING !!!: Never use on humans, dogs or cats


Risk of resistance? YES, in gastrointestinal roundworms in sheep (very high), goats (very high) and cattle (high) particularly in:

Resistance of gastrointestinal roundworms to ivermectin in sheep, goats and cattle has been reported almost worldwide, including the USA, UK, Australia and New Zealand. Based on the very abundant and frequent use of ivermectin and other macrocyclic lactones (with cross-resistance to ivermectin) in livestock it must be assumed that resistance of these roundworms to this chemical class will continue spreading and strengthening in the future.

This means that if this product does not achieve the expected efficacy against the mentioned parasites, it may be due to resistance and not to incorrect use, which is usually the most frequent cause of product failure.

Alternative chemical classes/active ingredients to prevent resistance of gastrointestinal roundworms through product rotation:

These alternative products may not be available in all countries, or may not be available as injectables.

Learn more about resistance and how it develops.


Are the active ingredients of this product ORIGINAL* or GENERICS**?


*Meaning that they are still patent protected and generics are not yet available
**Meaning that they have lost patent protection and may be acquired from manufacturers of generic active ingredients other than the holder of the original patent.

COUNTRIES where this product is marketed (maybe under another TM): Worldwide, including the US, Canada, the EU, Australia, etc., sometimes under the trade name IVOMEC CLASSIC.
GENERIC BRANDS available? YES, worldwide by the hundreds.

Click here to learn more about GENERIC vs. ORIGINAL drugs.

For an overview on the most used antiparasitic injectable brands for livestock click here.


IVOMEC 1% injectable is the mythical first brand of ivermectin launched by MS&D (later MERIAL) in the early 1980's. Ivermectin was the first macrocyclic lactone introduced in the market. It was a milestone and a tremendous progress that revolutionized the control of veterinary parasites in livestock. Nowadays there are thousands of brands with generic ivermectin worldwide.

There are also numerous mixtures of ivermectin with other active ingredients, as well as other formulations for topical (pour-on) and oral (drench, feed additives) administration.

Whereas IVOMEC 1% injectable is approved for use on cattle worldwide, approval for use on sheep, swine, goats and other minor species (e.g. bisons, deer, etc.) depends on the country. These differences are most likely due to MERIAL's marketing strategies in the different countries (e.g. market segmentation, local product portfolio, etc.) and not to regulatory hurdles.

All 1% ivermectin injectables used on cattle at the recommended dose of 200 mcg/kg offer a rather poor control of cattle ticks Boophilus (=Rhipicephalus) microplus, usually insufficient for most producers.

The different withholding periods in various countries illustrate the fact that unfortunately, national regulatory authorities often draw different conclusions from the same scientific evidence. This has been always so and there are no indications that things will improve in the near future.

Being one of the best antiparasitics ever developed, ivermectin does not control all parasites of livestock. Unfortunately advertising and even the label of some generic formulations in less developed countries often include unsubstantiated claims. To help preventing confusion and misuse it is useful to know that whatever ivermectin 1% injectable used at the recommended dose DOES NOT CONTROL:


This article IS NOT A PRODUCT LABEL. It offers complementary information that may be useful to veterinary professionals and users that are not familiar with veterinary antiparasitics. 

Information offered in this article has been extracted from publications issued by manufacturers, government agencies (e.g. EMEA, FDA, USDA, etc.) or in the scientific literature. No guarantee is given on its accuracy, integrity, sufficiency, actuality and opportunity, and any liability is denied. Read the site's DISCLAIMER.

In case of doubt contact the manufacturer or a veterinary professional.