Brand: VIRBAMEC ® LV Pour-on
PARASITES CONTROLLED (spectrum of activity)
- Gastrointestinal roundworms (adults and L4 larvae): Ostertagia ostertagi (incl. inhibited larvae), Haemonchus placei, Trichostrongylus axei, Cooperia onchophora, Cooperia punctata, Oesophagostomum radiatum, Bunostomum phlebotomum, Nematodirus spathiger, Strongyloides papillosus, Trichuris spp.
- Lungworms (adults and L4 larvae): Dictyocaulus viviparus.
- Sucking & biting lice: Linognathus vituli, Haematopinus eurysternus, Solenopotes capillatus, Bovicola (Damalinia) bovis
- Mites (scabies): Sarcoptes scabiei var. bovis, Chorioptes bovis.
- Buffalo flies: Haematobia irritans exigua.
- Cattle ticks: Boophilus microplus.
- Residual effect (significant country differences: read the product label!):
- Cattle: 500 mcg/kg bw, equivalent to 1 ml/20 kg (=22 lb) bw
- LD50 (acute oral) in rats: >2000 mg/kg
- LD50 (acute dermal) in rats: >2000 mg/kg
- Estimated hazard class according to the WHO: not applicable for veterinary medicines
Suspected poisoning? Read the article on ivermectin safety in this site.
Withholding periods (=withdrawal times) for meat & milk (country-specific differences may apply: read the product label)
- Meat: Australia 21 days (ESI 21 days)
- Milk for human consumption: NIL
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:
- Safety for humans
- Safety for domestic animals
- Safety for the environment
- Hazard classifications of pesticides
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.
- 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.
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 measures (e.g. rotation, IPM, etc.) are taken.
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 (maybe under another TM): Australia
GENERIC BRANDS available? YES, worldwide by the dozens.
Click here to learn more about GENERIC vs. ORIGINAL drugs.
For an overview on the most used antiparasitic pour-on brands click here.
VIRBAMEC LV Pour-on for Cattle from VIRBAC is one of the numerous pour-ons based on generic ivermectin. It contains 1% instead of 0.5% ivermectin, which is the most common concentration of ivermectin in pour-ons for cattle, but the recommended dose is the same, 500 mcg/kg bw.
The spectrum of activity is slightly different than the one of the 0.5% ivermectin formulations. The higher concentration has the benefit of a lower administration volume, but may reduce the coverage on the animal's hair coat, which is important for controlling certain external parasites.
Ivermectin was the first macrocyclic lactone introduced in the market in the early 1980s (by MSD Agvet, later MERIAL). It was a milestone and a tremendous progress that revolutionized the control of veterinary parasites. Nowadays there are thousands of brands with generic ivermectin worldwide. It is effective against most species of roundworms that affect cattle and against many external parasites (mainly lice, mites, buffalo flies, etc.), but not against tapeworms or flukes.
Besides convenience aspects, the ivermectin pour-on formulations have the advantage over the ivermectin 1% injectables that they also control buffalo flies, biting lice, and cattle ticks, which are not controlled by the 1% injectables.
But it has also disadvantages. 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 in gastrointestinal roundworms.
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.
In contrast with the ivermectin 1% injectables, the pour-on formulations 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-ons shouldn't be administered by strong winds that may blow away part of the product and/or contaminate the workers.
For all these reasons efficacy after pour-on administration is usually less reliable than after injection.
This 1% ivermectin pour-on formulation has a NIL withholding period for milk, i.e. it can be used on dairy cows producing milk for human consumption. This is in contrast with several other ivermectin pour-ons (and injectables), which are usually not approved for use on dairy cows in many countries. This is probably related to the recently approved ivermectin MRL in bovine milk (= 10 ppb = 0.01 mg/kg) by some registration bodies (incl. CODEX), which has not yet been adopted everywhere. In the past such an ivermectin MRL for bovine milk was not set at all, and as a consequence any ivermectin residues in milk were illegal. In the absence of an MRL most manufacturers didn't even test the behavior of their ivermectin formulations in dairy cows, i.e. they had no data on milk residues at all: The only possible use recommendation was not to use the product on dairy cows. Now that an MRL is set, manufacturers can generate data and present them to the registration authorities in order to get the approval of a withholding period for milk. Some manufacturers may present such data for their ivermectin products, some may not, or not for all their ivermectin products, for whatever reasons.
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 0.5% pour-on formulation (without additional active ingredients) used at the recommended dose of 500 mcg/kg bw DOES NOT CONTROL:
- Most ticks (e.g. Amblyomma spp, Rhipicephalus spp, Dermacentor spp, Haemaphysalis spp, Hyalomma spp, Ixodes spp, etc.)
- Flies other than buffalo flies (e.g. houseflies, stable flies, black flies, horse flies, etc.)
- Fleas (e.g. Ctenocephalides spp)
- Tapeworms (e.g. Moniezia spp)
- Flukes (e.g. liver fluke Fasciola hepatica)
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