Brand: VETMED DORAMECTIN Pour-on for Cattle
FORMULATION: «pour-on» for topical administration.
ACTIVE INGREDIENT(S): doramectin 5 mg/mL (=0.5%)
CHEMICAL CLASS of the active ingredient(s): macrocyclic lactone
PARASITES CONTROLLED* (spectrum of activity)
* Country-specific differences may apply: read the product label.
- Gastrointestinal roundworms (mature and immature):
- Barber’s Pole Worm: Haemonchus placei
- Small Brown Stomach Worm: Ostertagia ostertagi (incl. inhibited larvae)
- Black Scour Worm: Trichostrongylus colubriformis
- Stomach Hair Worm: Trichostrongylus axei
- Small Intestinal Worm (incl. inhibited larvae): Cooperia oncophora, C. punctata, C. surnabada
- Thin-Necked Intestinal Worm: Nematodirus spathiger (adults only)
- Nodule Worm: Oesophagostomum radiatum
- Hookworm: Bunostomum phlebotomum (adults only)
- Whipworm: Trichuris spp (adults only)
- Lungworms (adults and immature): Dictyocaulus viviparus.
- Sucking & biting lice: Linognathus vituli, Solenopotes capillatus, Haematopinus eurysternus, Bovicola (Damalinia) bovis.
- Residual effect (significant country differences: read the product label!):
- Dictyocaulus viviparus, Ostertagia ostertagi, Trichostrongylus axei Oesophagostomum radiatum, Cooperia oncophora up to 28 days.
- Oesophagostomum radiatum, Cooperia spp, Bunostomum phlebotomum up to 21 days.
- Cattle: 500 mcg doramectin/kg bw (= 227 mcg/lb), equivalent to 1 ml product/10 kg bw
* Can be slightly different in some countries: read the product label!
- LD50 (acute oral) in rats: 50 mg/kg fr the a.i.
- stimated hazard class according to the WHO: not applicable for veterinary medicines
Suspected poisoning? Read the article on doramectin safety in this site.
Withholding periods (=withdrawal times) in days for meat & milk (country-specific differences may apply: read the product label)
- Meat: New Zealand 36 days.
- Milk for human consumption: New Zealand: NIL
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? YES, reported in gastrointestinal roundworms in cattle in several countries, particularly in the following worm species: Cooperia spp and Ostertagia spp.
Resistance of gastrointestinal roundworms to macrocyclic lactones in sheep, goats and cattle has been reported in numerous countries. Most cases have been reported for ivermectin, but doramectin shows cross-resistance with ivermectin. 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:
- 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.
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: New Zealand
GENERIC BRANDS available? Yes a few ones. This product contains itself generic doramectin.
Click here to learn more about GENERIC vs. ORIGINAL drugs.
For an overview on the most used antiparasitic pour-on brands click here.
VETMED DORMECTIN Pour-on for cattle is a local brand from NEXAN with generic doramectin. It is a generic version of DEXTOMAX POUR ON from ZOETIS.
Doramectin is a broad spectrum macrocyclic lactone introduced in the 1990s (by PFIZER, now ZOETIS) for use in livestock. It's spectrum of activity is similar to that of ivermectin. It 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 allows higher safety margins. It is not used in poultry, only marginally in horses, and not at all in pets. It is not used in agriculture.
Pour-ons with macrocyclic lactones have some general disadvantages over injectables. 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 doramectin pour-ons, but it must be assumed that the licking-behavior of cattle affects intake of doramectin 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.
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 injectables, 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-on shouldn't be administered by strong winds that may blow away part of the product and/or contaminate the workers.
For these reasons efficacy after pour-on administration is usually less reliable than after injection.
There are other doramectin formulations for injectable administration, mainly for cattle and sheep.
Being an excellent antiparasitic, comparable to ivermectin, doramectin 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 doramectin pour-on (without additional active ingredients) used at the recommended dose of 500 mcg/kg DOES NOT CONTROL:
- Ticks other than cattle ticks (e.g. Amblyomma spp, Rhipicephalus spp, Dermacentor spp, Haemaphysalis spp, Hyalomma spp, Ixodes spp, etc.)
- Flies other than horn & 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.