Brand: LONGRANGE ™ Injection for Cattle


FORMULATION: «injectable» solution to be administered subcutaneously in front of the shoulder.

ACTIVE INGREDIENT(S): eprinomectin: 50 mg/mL (=5%)

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


PARASITES CONTROLLED* (spectrum of activity)

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


  • Cattle: 1 mg/kg bw, equivalent to 1 ml/50 kg (=110 lb) bw


  • LD50 (acute oral) in rats: 55 mg/kg (for the a.i.)
  • LD50 (acute dermal) in rats: not available
  • Estimated hazard class according to the WHO: not applicable for veterinary medicines

Suspected poisoning? Read the article on eprinomectin safety in this site.

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

  • Meat: USA: 48 days
  • Milk for human consumption: not approved. Not approved for use in female dairy cattle 20 months of age or older, including dry dairy cows.

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


Risk of resistance? YES, reported for ivermectin in gastrointestinal roundworms in cattle in several countries, particularly in the following worm species: Cooperia spp, Ostertagia spp, Haemonchus spp, Trichostrongylus spp, Oesophagostomum spp, whereby cross-resistance between eprinomectin and ivermectin must be assumed.

Based on the very abundant and frequent use in cattle of ivermectin and other macrocyclic lactones (with cross-resistance to ivermectin) 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 pour-ons.

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 brand/product is marketed: USA, Canada
GENERIC BRANDS available? So far not available in most countries. Generics of the pour-on formulation (EPRINEX) are available in some countries (e.g. in Latin America).

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

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


LONGRANGE extended-release injection for cattle was introduced by MERIAL in the USA in 2012. It contains eprinomectin formulated in microspheres that ensure a slow release of the active ingredient for a period of up to 100 days. This technology for injectable drugs (called THERAPHASE) was developed by PR Pharmaceuticals.

Eprinomectin was one of the last macrocyclic lactones introduced in the 1990s (by MERIAL). It was the first macrocyclic lactone approved for use on dairy cows because it does not leave significant residues in milk, in contrast with all ivermectin-based products. Nowadays other macrocyclic lactones (e.g. doramectin, moxidectin) have been approved for use on dairy cows in some countries. The spectrum of activity of eprinomectin is similar to that of ivermectin and other macrocyclic lactones: mainly roundworms, lice and mites and, delivered as a pour-on, also some fly and tick species. It is ineffective against tapeworms and flukes. Eprinomectin is moderately used in cattle but not in other livestock. It is marginally used in cats, but not in dogs. It is not used in agriculture.

The major benefit of LONGRANGE when compared with either the 1% ivermectin injectable (IVOMEC) or the 0.5% eprinomectin pour-on (EPRINEX) is the 3 to 5 months protection against key gastrointestinal roundworms (mainly Cooperia spp, Haemonchus placei, Ostertagia spp, Trichostrongylus spp) and lungworms (Dictyocaulus viviparus). But it is not approved for dairy cows and several important roundworms such as threadworms (Strongyloides spp), whipworms (Trichuris spp) and eyeworms (Thelazia spp), as well as sucking or biting lice are not included in the label.

Interestingly, eprinomectin was the first macrocyclic lactone approved for use on dairy cows (only as a pour-on) because it does not leave significant residues in milk, in contrast with all ivermectin-based products. But LONGRANGE is not approved for use on dairy cows. The reason is probably that after injection at a dose of 1 mg/kg residues in milk remain for a long time over the MRL approved for eprinomectin in milk, in contrast with the low residues after topical administration at the usual pour-on dose of 0.5 mg/kg.

These long-acting injectables have vastly replaced the former ivermectin slow-release boluses, no more marketed today in most countries.

Besides numerous 3.15% ivermectin injectables, other long-acting injectables for cattle are also available with moxidectin (another macrocyclic lactone) in some countries (e.g. in Australia and Latin America).

Click here for general information on good practices for the prevention and control of gastrointestinal worms in livestock.


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