Brand: CYDECTIN ® Long Acting Injection for Cattle


FORMULATION: «injectable» to be administered subcutaneously in the ear

ACTIVE INGREDIENT(S): moxidectin: 100 mg/mL (=10.0%)

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


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: 1 mg/kg bw, equivalent to 1 ml/100 kg (=220 lb) bw. Do not retreat for at least 56 days after administration. Do not use in cattle < 100 kg and >500 kg bw
  • Read the product label for further details on dosing


  • LD50 (acute oral) in rats: 1060 mg/kg (estimate according to WHO 2009 recommendation)
  • LD50 (acute dermal) in rats: >2000 mg/kg (for the a.i., source MSDS)
  • Estimated hazard class according to the WHO: not applicable for veterinary medicines

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

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

  • Meat: UK: 108 days Australia: 56; Export Slaughter Interval (ESI): 108 days
  • Milk for human consumption: UK: not approved. Australia: 80 days.

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


Risk of resistance? YES, in gastrointestinal roundworms in cattle (high) particularly in:

Resistance of gastrointestinal roundworms to macrocyclic lactones in cattle has been reported in numerous countries. Most cases have been reported for ivermectin, and moxidectin often works well against ivermectin-resistant worms initially. But if moxidectin use continues gastrointestinal roundworms will become resistant to it rather quickly. Based on the very abundant and frequent use of ivermectin and other macrocyclic lactones in livestock (with more-or-less cross-resistance to ivermectin) it must be assumed that resistance of gastrointestinal 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.

Resistance of cattle ticks Rhipicephalus (Boophilus) microplus to ivermectin has been reported in several Latin American countries. It is not yet a widespread problem, but nevertheless a warning. Based on the intensive use of macrocyclic lactones on cattle it is only a matter of time for resistance of cattle ticks to these compounds to develop elsewhere unless specific resistance preventative meaures (e.g. rotation, IPM, etc.) are taken.

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: UK, Ireland & EU countries, Australia, New Zealand. In some countries marketed by ZOETIS, in other countried by VIRBAC
GENERIC BRANDS available? NO, for most countries 

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


CYDECTIN LONG ACTING INJECTION (10%) for CATTLE is a brand marketed by VIRBAC in Australia and by ZOETIS in the UK an other EU countries. Interestingly neither this brand, nor comparable products with such a high moxidectin concentration are marketed in the USA so far. It may be related with regulatory hurdles due to excessive residues, but also with marketing reasons.

Moxidectin is a macrocyclic lactone introduced in the 1990s (by AMERICAN CYANAMID). It is moderately used in livestock and pets, but not in agriculture. Its spectrum of activity is similar to the one of  ivermectin, i.e. basically roundworms and certain external parasites (mites, lice, etc.). As all other macrocyclic lactones moxidectin is not effective against tapeworms and flukes. Moxidectin is generally considered as more potent than ivermectin against gastrointestinal nematodes of livestock, particularly in sheep and goats, and against a few other livestock pests (e.g. sheep scab, cattle ticks, etc.). It is also less toxic than ivermectin, which makes it possible to use it at higher rates, particularly in long-acting formulations. Moxidectin is moderately used in livestock and horses, but rather scarcely in pets. It is not used in agriculture.

Major advantage of CYDECTIN LONG ACTING INJECTION (10%) for CATTLE is obviously the extended protection against important parasites, much longer than for the 1% moxidectin injectable, or similar injectables with other macrocyclic lactones. The major drawback is the longer withholding period when compared with the 1% moxidectin injectable.

There are other moxidectin formulations for topical (pour-on) and oral (drench) administration, mainly for cattle and sheep, but not at such higher concentrations. So far there are no moxidectin products for use on swine.

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

Being an excellent antiparasitic, moxidectin even at such high concentrations does not control all parasites of cattle. Used at the recommended dose the moxidectin 10% injectable 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.