Brand: AVOMEC ® PLUS Pour-on
CHEMICAL CLASS of the active ingredient(s):
PARASITES CONTROLLED (spectrum of activity)
- Gastrointestinal roundworms (adults and immature stages): Ostertagia ostertagi (incl. inhibited larvae), Haemonchus placei, Trichostrongylus axei, Cooperia oncophora, Cooperia punctata, Oesophagostomum radiatum (adults), Nematodirus spathiger, Bunostomum phlebotomum, Trichuris spp, Strongyloides papillosus.
- Lungworms: Dictyocaulus viviparus.
- Flukes: Liver fluke, Fasciola hepatica adults + immature stages.
- Sucking & biting lice: Haematopinus eurysternus, Linognathus vituli, Solenopotes capillatus, Bovicola (Damalinia) bovis.
- Aids in the control of cattle ticks (Boophilus microplus) and buffalo flies (Haematobia irritans exigua).
- 1 ml product/10 kg (=22 lb) bw, equivalent to: abamectin 0.5 mg/kg bw, and triclabendazole 30 mg/kg bw
- LD50 (acute oral) in rats:
- abamectin: a.i. 10 mg/kg (according to MSDS)
- triclabendazole: a.i. >8000 mg/kg (according to MSDS)
- LD50 (acute dermal) in rats:
- abamectin: a.i. 330 mg/kg (according to MSDS)
- triclabendazole: a.i. >4000 mg/kg (according to MSDS)
- Estimated hazard class according to the WHO: not applicable for veterinary medicines
Withholding periods (=withdrawal times) in days for meat & milk (country-specific differences may apply: read the product label)
- Meat: Australia 49 days (ESI 140 days)
- Milk for human consumption: DO NOT USE in dairy animals producing or which will in the future be producing milk for human consumption.
WARNING !!!: Never use on humans, dogs or cats
You may be interested in the following articles in this site dealing with the general safety of veterinary products:
- Safety for humans
- Safety for domestic animals
- Safety for the environment
- Hazard classifications of pesticides
Risk of resistance of gastrointestinal roundworms to macrocyclic lactones (incl. abamectin): YES, reported in cattle in numerous countries particularly in the following worm species: Cooperia spp and Ostertagia spp.
Resistance of gastrointestinal roundworms to macrocyclic lactones (incl. abamectin) 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.
- Benzimidazoles, e.g. albendazole, febantel, fenbendazole, oxfendazole, etc. Similar or even worse resistance problems than ivermectin
- Imidazothiazoles, mainly levamisole. etc. Similar or even worse resistance problems than ivermectin
- Nitroxinil (limited spectrum of activity)
- Tetrahydropyrimidines, e.g. morantel, pyrantel (limited spectrum of activity)
- Salicylanilides, e.g. closantel (limited spectrum of activity)
These alternative products may not be available in all countries, or may not be available as pour-ons.
Risk of resistance liver flukes to triclabendazole: YES. Resistance of liver flukes to triclabendazole (and albendazole) in sheep was already discovered in the mid 1990's in Australia. Since then it has been reported in several other countries (e.g. New Zealand, UK, Ireland, Spain, Argentina), also in cattle (e.g. Australia, The Netherlands, Argentina). However, the incidence so far is not that serious as for roundworm resistance to benzimidazoles and other nematicides. Nevertheless, in certain regions products with triclabendazole may not protect livestock adequately against liver flukes.
These alternative products may not be available in all countries, may not be available as pour-ons, or may not have the same spectrum of efficacy as AVOMEC PLUS.
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.
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: Australia.
GENERIC BRANDS available? Yes a few ones, but not in all countries in this particular composition and as a pour-on. Similar combinations of triclabendazole with other macrocyclic lactones are also available as drenches.
Click here to learn more about GENERIC vs. ORIGINAL drugs.
For an overview on the most used antiparasitic pour-on brands click here.
AVOMEC PLUS Pour-on for cattle from MERIAL is one of the numerous combinations of "endectocide + flukicide" for simultaneously controlling roundworms, flukes and external parasites in cattle. It is the same product as ANCARE's GENESIS ULTRA Pour-on in Australia, which is also marketed under this trade name in New Zealand.
Abamectin, a veteran endectocide introduced in the 1980s (by MSD AgVet → MERIAL), is considered as the "cheap" macrocyclic lactone. It is less potent and more toxic than ivermectin and other macrocyclic lactones but is often "good enough", with a similar spectrum of activity as ivermectin. Interestingly abamectin is widely used on livestock and horses in Australia and New Zealand but so far not in the EU (excepting preciselyy this formulation), the USA and Canada. As for other macrocyclic lactones, abamectin has no efficacy whatsoever against tapeworms and flukes. It is moderately used in livestock, much less in horses and pets. It is also used against agricultural pests.
Triclabendazole is a narrow-spectrum benzimidazole introduced in the 1970s (by CIBA-GEIGY). It has no efficacy against roundworms or tapeworms. However it was and remains the only flukicide effective against adults as well as all immature stages of liver flukes, which are the most damaging stages due to their destructive migration through the liver tissues. For this reason it has been for decades and still remains the most widely used livestock flukicide worldwide. It is ineffectivy against any external parasites (ticks, flies, lice, mites, etc) of livestock. It is abundantly used in ruminants, but not in other livestock, horses or pets. It is also used in human medicines. It is not used in agriculture.
It is useful to know that pour-on administration of parasiticides has some disadvantages when compared with injectables and drenches. In several scientific studies it has been shown that ivermectin administered as a pour-on is not "automatically" absorbed through the skin. Licking (self licking or licking of other treated animals) may account for >50% of the total intake, compared with only about 10% absorbed directly through the skin. This is the reason why a dose of 500 mcg/kg bw is needed after pour-on treatment, compared with only 200 mcg/kg bw after injection. And it has been also shown that intake of topically administered active ingredient in some cattle may be twice as high as in other ones, all treated at the same rate. The reason is that individual cattle show a different licking behavior. An important practical consequence is that the quantity that is finally ingested and is therefore available for the control of gastrointestinal worms depends on the licking behavior of the treated animals. "High lickers" can be overdosed, whereas "low lickers" can be underdosed. And chronic underdosing of animals in a herd may enhance development of resistance to ivermectin and other macrocyclic lactone in gastrointestinal roundworms.
To our knowledge similar studies have not been carried out with the abamectin pour-ons, but it must be assumed that the licking-behavior of cattle affects intake of abamectin in a comparable way. A similar effect of the licking behavior on the intake of active ingredient after pour-on administration has also been shown for fluazuron, a tick development inhibitor.
It is likely that licking and grooming also plays an important role in the intake of triclabendazole administered as a pour-on to cattle. The higher dose of 30 mg triclabendazole/kg bw after pour-on administration when compared with the usual dose of 12 mg/kg bw after oral administration (drench) reflects the fact that absorption of triclabendazole through the skin is also significantly lower than after oral administration.
Absorption through the skin is also negatively affected by the thickness of the skin and the hair coat, by dust and mud on the coat, by product lost on fences and yards, etc, factors that don't play a role after injection. The pour-on formulation should not be administered to wet animals, and rain shortly before (up to 6 hours) or after administration can cause product run-off and thus under-dosing. The pour-on shouldn't be administered by strong winds that may blow away part of the product and/or contaminate the workers.
Click here for general information on good practices for the prevention and control of gastrointestinal worms in livestock.
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