Brand: WORMA DRENCH ®
Company: INTERNATIONAL ANIMAL HEALTH PRODUCTS
DELIVERY FORM: «drench» for oral administration.
ACTIVE INGREDIENT(S): oxfendazole 100 g/L (equivalent to 10%).
CHEMICAL CLASS of the active ingredient(s): benzimidazole
INDICATIONS: CATTLE & HORSES
PARASITES CONTROLLED* (spectrum of activity)
* Country-specific differences may apply: read the product label.
- Dairy & Beef - Small Brown Stomach Worm (Ostertagia ostertagi ) including inhibited fourth larval or hypobiotic stages, Barber's Pole Worm (Haemonchus placei) , Small Intestinal Worm (Coperia spp), Stomach hairworm (Trichostrongylus axei,), Thin Necked Intestinal Worm (Nematodirus spp), Hookworm (Bunostomum phlebotomum), Nodule Worm (Oesophagostomum radiatum), Lungworm (Dictyocaulus viviparus), and Cattle Tapeworm (Moniezia spp).
- Mature & immature stages of Bloodworm (Strongylus vulgaris); Large Strongyles or Redworms, including the migratory tissue stages of Strongylus edentatuss; Large Roundworm (Parascaris equorum), Pinworms (Oxyuris equi), Small redworms (Small strongyles or Cyathostome species susceptible to oxfendazole), mature Stomach Worms (Habronema microstoma), as well as the harmful migrating stages of the Bloodworm (Strongylus vulgaris) (55-88% activity) with corresponding reduction in arterial lesions.
* Country-specific differences may apply: read the product label.
- Cattle: 5 mL product/100 kg bw (equivalent to 5 mg of oxfendazole/kg).
- Horses: 10 mL product/100 kg bw (equivalent to 10 mg of oxfendazole/kg).
- LD50 (acute oral) in rats: >6400 mg/kg (for the a.i.)
- LD50 (acute dermal) in rats: n.a.
Suspected poisoning? Read the article on oxfendazole safety in this site.
Withholding periods (=withdrawal times) in days for meat & milk (country-specific differences may apply: read the product label)
- Cattle: AUS: Meat 8 days.
- Horses: AUS 28 days
- Milk for human consumption: AUS 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, resistance of gastrointestinal roundworms to all benzimidazoles (incl. oxfendazole) is a very serious and increasing problem worldwide, particularly in sheep and goats, but also in cattle and horses. The most affected worm species are:
- Horses: Cyathostomins
- Cattle: Cooperia spp, Haemonchus spp, Ostertagia spp, Trichostrongylus spp, Oesophagostomum spp.
This means that if this product does not achieve the expected efficacy against the mentioned parasites, it can 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:
- Macrocyclic lactones (e.g. abamectin, doramectin, eprinomectin, ivermectin, moxidectin, etc.). Resistance to macrocyclic lactones is also increasing and strengthening quickly in many countries.
- Levamisole. Resistance to levamisole has been reported in most countries, but is usually less strong and frequent than to benzimidazoles.
- Salicylanilides (e.g. closantel): effective only against certain gastrointestinal roundworms. Not available in some countries. Resistance to closantel has been reported in some countries.
- Tetrahydropyrimidines (e.g. morantel, pyrantel): effective only against certain gastrointestinal roundworms. Not available in some countries. Resistance to morantel has been reported in some countries.
- Nitroxinil: effective only against certain gastrointestinal roundworms (e.g. Bunostomum spp, Haemonchus spp, Oesophagostomum spp). Not available in some countries.
These alternative products may not be available in all countries, or may not be available as drenches, or may not be effective against all the concerned parasites.
There are only very few reports on resistance of Moniezia spp tapeworms to benzimidazoles but it is certainly not a widespread problem so far.
It is highly recommended to periodically check the resistance status of each property performing appropriate tests (e.g. fecal egg counts) under supervision of a veterinary doctor. Such tests are now routinely available for most producers in developed countries.
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: Australia
GENERIC BRANDS available? Yes, in most countries
Click here to learn more about GENERIC vs. ORIGINAL drugs.
For an overview on the most used drench brands for livestock click here.
This product is a classical drench for cattle & horses from INTERNATIONAL ANIMAL HEALTH PRODUCTS with generic oxfendazole.
Oxfendazole is a veteran broad-spectrum benzimidazole (introduced in the 1970s by WELLCOME, SYNTEX). It is effective against roundworms (gastrointestinal and pulmonary) & tapeworms, but is ineffective against flukes. Oxfendazole also kills eggs of roundworms (ovicidal activity). As all benzimidazoles, oxfendazole has no efficacy whatsoever against external parasites (ticks, flies, lice, mites, etc). Among the benzimidazoles oxfendazole is quite comparable with fenbendazole in terms of efficacy and safety. It is moderately used in livestock, scarcely in horses and pets.It is not used in agriculture.
As all benzimidazoles (as well as other anthelmintics such as levamisole, monepantel, and tetrahydropyrimidines), oxfendazole administered as a drench has no residual effect, i.e. it kills the parasites shortly after administration, but does not significantly protect the animals against re-infestation by infective stages in their environment.
Drench is the preferred delivery form for use on cattle, sheep and goats, but in many countries it is also available in the form of feed additives (mainly for pig & poultry) and other delivery forms for oral administration (boluses, tablets, pastes, etc). As most benzimidazoles it is not appropriate for intramuscular or subcutaneous injection due to its poor solubility in water, but intraruminal injection is very popular in Latin America.
Oxfendazole is sometimes used in combinations that broaden the spectrum of activity or try to overcome potential resistance. Typical mixtures for livestock include a flukicide (e.g. closantel, etc.) and/or a macrocyclic lactone, and/or levamisole, although such mixtures are not approved everywhere.
Unfortunately, resistance of several gastrointestinal roundworms to all benzimidazoles (including oxfendazole) is already very high and very frequent worldwide in sheep and goats, slightly lower in cattle, which has significantly reduced their usage in livestock. Nowadays more convenient pour-ons and injectables containing macrocyclic lactones (e.g. abamectin, doramectin, eprinomectin, ivermectin, moxidectin) are often preferred over drenches with benzimidazoles. Macrocyclic lactones also ensure several weeks protection against re-infestation by several worm species, in contrast with all benzimidazoles that lack any residual effect.
In ruminants, reducing the amount of feed slows down the exit flow of the rumen and prolongs the time during which the active ingredient remains there and is absorbed. Consequently it is advisable to reduce the access of animals to feed (especially to fresh pasture, not to water) 24 hours before administration. For the same reason, it is better to keep the animals away from food for about 6 hours after drenching. However sick or weak animals should not be kept away from food and fasting animals should have access to water. In cattle, a fiber-rich diet also increases the bioavailability of oxfendazole.
Oxfendazole active ingredient is a solid compound poorly soluble in water and in drenches it is formulated as a suspension (not as a solution or as an emulsion). A key unfavorable feature of all suspensions is that the suspended solid particles tend to fall down to the bottom of the container and sediment, very much like sand in water. This means that suspensions must be thoroughly shaken before use. How fast the suspension sediments and how easily shaking the container redistributes the suspension depends on the formulation quality. A good formulation sediments slowly and shaking will re-suspend it quickly. Bad formulations sediment quickly and shaking re-suspends them slowly.
Thoroughly shaking suspensions before use is crucial for efficacy. If the active ingredient remains in the sediment, a few animals may get most of the active ingredient and will be overdosed, and the large majority will get almost only solvents and will be underdosed.
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.
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