Brand: ALVERIN™ PLUS Injection

Company: ZOETIS

FORMULATION: «injectable» to be administered subcutaneously under the loose skin in front of, or behind the shoulder in cattle.


CHEMICAL CLASSES of the active ingredient(s):


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!

  • 1 ml product/50 kg (=110 lb) bw, corresponding to:


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

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

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

  • Meat: USA 49 days. Do not use in calves to be processed for veal.
  • Milk: USA: do not use in female dairy cattle of breeding age.

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

You may be interested in the following articles in this site dealing with the general safety of veterinary products:


Risk of resistance? YES, in gastrointestinal roundworms in cattle particularly in: Cooperia spp, Haemonchus spp, Oesophagostomum spp, Ostertagia spp, Trichuris spp

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.

There are a few reports on liver fluke (Fasciola hepatica) resistance to clorsulon in sheep, but so far it is not such an extended problem as for gastrointestinal roundworms. To our knowledge there are no published reports on resistance of liver fluke (Fasciola hepatica) to clorsulon in cattle.

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): US, New Zealand
GENERIC BRANDS available? YES, abundant. ALVERIN PLUS is itself a generic versions of MERIAL's IVOMEC PLUS = IVOMEC SUPER.

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

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


ALVERIN PLUS Injection for Cattle is one of the numerous brands containig 1% ivermectin + 10% clorsulon, in this case manufactured by NORBROOK and marketed in the USA by ZOETIS.

Ivermectin is a broad spectrum parasiticide with efficacy against internal parasites (mainly roundworms) and against external parasites as well (mainly mites, lice, grubs, etc). This is why it is called an endectocide (controls endoparasites and ectoparasites). Ivermectin was the first macrocyclic lactone discovered and introduced in the 1980s by MS&D AgVet. It is the parasiticide for livestock and pets most widely used worldwide, with probably thousands of generic brands. Ivermectin is probably the best veterinary parasiticide ever developed, highly effective against roundworms as well as against numerous external parasites (ticksflies, lice, mites, etc.). As all macrocyclic lactonesivermectin used alone is ineffective against tapeworms and flukes, regardless of the delivery form. It is massively used in livestock and horses, less in pets. It is also used in agriculture and against household pests.

Clorsulon is a veteran flukicide introduced in the 1970s (by MS&D-AGVET), a benzenesulphonamide with a narrow spectrum of efficacy against a few trematode species. It has no efficacy whatsoever against roundworms (gastrointestinal, pulmonary, ocular, etc.) or tapeworms, nor against external parasites of cattle (mites, lice, ticks, grubs, etc). It is moderately used in cattle, not at all in sheep, goats, horses, swine, poultry or pets. It is not used in agriculture.

The reason for mixing clorsulon to ivermectin is adding efficacy against liver flukes (Fasciola hepatica), because ivermectin is not effective against any fluke species. However, at the dose rate used in this product clorsulon ensures efficacy only against the adult stages of Fasciola hepatica, but not against larvae. This is important because the most damaging stages of Fasciola hepatica are precisely the larvae migrating through the liver tissues. Adult liver flukes dwell mainly in the biliary ducts and are also damaging to cattle but substantially less than immature stages. Consequently cattle treated with this product won't be protected against immature liver flukes. There are products containing clorsulon that are also effective against late immature stages (≥8 weeks) of Fasciola hepatica, (e.g. various drenches). So far only flukicides containing triclabendazole are effective against all immature stages (≥1 week) of Fasciola hepatica, but are only available as drenches or pour-ons, not as injectables. and not in all countries (e.g. not aapproved in the USA). However, cases of resistance of Fasciola hepatica to triclabendazole in cattle have already been reported in several countries (e.g. Australia, The Netherlands, Argentina, Peru).

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% + clorsulon 10% injectable formulation administered at the usual recommended dose of 1 ml/50 kg bw DOES NOT CONTROL:

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.