Brand: TRIO ® SHEEP
- Abamectin: 1.0 mg/mL (equivalent to 0.1%)
- Levamisole hydrochloride: 40 mg/mL (equivalent to 4.0%)
- Albendazole: 25 mg/mL (equivalent to 2.5%)
- Iodine 1 mg/mL, Cobalt 0.2 mg/mL, Copper 2.1 mg/mL, Zinc 0.6 mg/mL , Selenium 0.5 mg/mL: without anthelmintic efficacy.
CHEMICAL CLASS of the active ingredient(s):
PARASITES CONTROLLED* (spectrum of activity)
* Country differences may apply: read the product label!
- Adult and immature gastrointestinal roundworms:
- Barber’s Pole Worm: Haemonchus contortus (incl. L4 inhibited larvae)
- Small Brown Stomach Worm: Teladorsagia (Ostertagia) circumcincta (incl. L4 inhibited larvae)
- Black Scour Worm: Trichostrongylus vitrinus
- Stomach Hair Worm: Trichostrongylus axei
- Small Intestinal Worm: Cooperia spp
- Thin-Necked Intestinal Worm: Nematodirus spp
- Large Mouthed Bowel Worm: Chabertia ovina
- Large Bowel Worm: Oesophagostomum venulosum, Oesophagostomum columbianum
- Whipworm: Trichuris ovis
- Intestinal threadworm: Strongyloides papillosus
- Hookworm. Bunostomum spp
- Barber’s Pole Worm: Haemonchus contortus (incl. L4 inhibited larvae)
- Lungworms: Dictyocaulus filaria
- Tapeworms:Moniezia spp
- Liver Fluke: Fasciola hepatica, adults
- Itch mite: Psorergates ovis
- Nasal Bot: Oestrus ovis
1 ml product per 5 kg bodyweight, equivalent to:
- 0.2 mg/kg abamectin
- 5 mg/kg albendazole
- 8 mg/kg levamisole hydrochloride (6.8 mg levamisole)
Read the product label for further details on dosing
- LD50 (acute oral) in rats:
- Abamectin: 10 mg/kg (for the a.i.)
- Albendazole: 1500 mg/kg (for the a.i.)
- Levamisole: 180 mg/kg (for the a.i.)
Withholding periods (=withdrawal times) for meat & milk (country-specific differences may apply: read the product label)
- Meat: New Zealand: 14 days
- Milk for human consumption: New Zealand: Milk intended for sale for human consumption must be discarded during treatment and for not less than 35 days following the last treatment.
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
Unfortunately, resistance of several gastrointestinal roundworms to abamectin (and other macrocyclic lactones), albendazole (and other benzimidazoles) and levamisole is already very high and very frequent worldwide in sheep and goats. Cases of multiple resistance (i.e. simultaneous) to two or even three of these chemical classes have also been reported. Most affected worm species in sheep are: Haemonchus spp, Ostertagia spp /Teladorsagia spp, Trichostrongylus spp, Nematodirus spp, Chabertia ovina.
Resistance of the liver fluke, Fasciola hepatica, to albendazole and triclabendazole has been already reported in several countries as well (e.g. Argentina, Australia, Ireland, The Netherlands, Spain, etc.). It is not as widespread and high as in gastrointestinal roundworms, but it will certainly strengthen and spread quickly unless measures are taken to delay it.
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.
It is generally accepted that the use of mixtures of active ingredients with different modes of action against a given parasite can delay the appearance of resistance. But only if the concerned parasites are susceptible to all the actives in the mixture. If not, the mixture is likely to promote multi-resistant parasites, because the selection pressure against all actives remains in place. Mixtures such as this one may provide peace-of mind to those users that do not know the resistance status of worms in their property: at least one of the actives will work... This may be the case for a while. But the risk that some worm species become resistant to all components after a few years using the same or comparable mixtures is considerable. If it is not too late, a better alternative is to determine the resistance status in the property and to rotate among products (not mixtures) against which the worms have not yet developed resistance, stopping the use of those chemical classes that have already shown resistance problems.
- Derquantel: available so far only for sheep in combination with abamectin.
- Monepantel: available only for sheep & goats in some countries (e.g. Australia, UK & EU, New Zealand). First cases of resistance reported in New Zealand in 2013.
- 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.
- Closantel (salicylanilide): effective only against ≥8 weeks old liver flukes.
- Clorsulon: effective only against ≥8 weeks old liver flukes.
- Nitroxinil: effective only against ≥8 (sheep) or ≥7 (cattle) weeks old liver flukes. Not available in some countries.
- Oxyclozanide (salicylanilide): effective only against ≥12 (sheep) or ≥10 (cattle) weeks old liver flukes. Not available in some countries.
- Rafoxanide (salicylanilide): effective only against ≥6 weeks old liver flukes. 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.
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.
Are the active ingredients of this product ORIGINAL* or GENERICS**?
- Abamectin: GENERIC (introduced in the 1980s)
- Albendazole: GENERIC (introduced in the 1970s)
- Levamisole: GENERIC (introduced in the 1960s)
*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, in Australia and New Zealand, not elsewhere. This product itself contains generic active ingredients.
Click here to learn more about GENERIC vs. ORIGINAL drugs.
For an overview on the most used drench brands for livestock click here.
TRIO SHEEP is a drench brand from RAVENSDOWN combining 3 active ingredients with different modes of action against gastrointestinal worms of sheep: abamectin, albendazole, and levamisole hydrochloride.
Abamectin, one of the first macrocyclic lactones developed, was introduced already in the 1980s (by MSD AGVET). As all macrocyclic lactones, abamectin is an endectocide, i.e. it is simultaneously effective against some external parasites and against internal parasites (mainly roundworms). As for other macrocyclic lactones, abamectin has no efficacy whatsoever against tapeworms and flukes. Abamectin is considered as the "cheap" ivermectin, with a similar spectrum of efficacy but less potent and slightly more toxic. It is abundantly used in ruminants, much less in pig, poultry and pets. Abamectin is also used in agricultural and hygiene pesticides worldwide. Interestingly abamectin is widely used on livestock in Australia and New Zealand but insignificantly in the EU, the USA and Canada.
Albendazole is a veteran benzimidazole introduced in the 1970's by SMITH-KLINE (later PFIZER, now ZOETIS). Albendazole was the first benzimidazole with a broad-spectrum of activity, i.e. effective against all three major classes of parasitic worms: Roundworms (gastrointestinal and pulmonary), tapeworms, and flukes (only adults). Most other benzimidazoles are not effective against flukes, and the oldest ones are also ineffective against tapeworms. Albendazole also kills eggs of roundworms and flukes (ovicidal activity). All this made albendazole particularly popular for use on livestock. As other benzimidazoles, albendazole has no efficacy whatsoever against external parasites (ticks, flies, lice, mites, etc). However, albendazole is not effective against acute fasciolasis of sheep caused by massive infections with larvae of Fasciola hepatica migrating through the liver. The reason is that albendazole is not effective against larval stages of Fasciola hepatica. A significant disadvantage of albendazole is that it can be teratogenic (other benzimidazoles too, e.g. ricobendazole, parbendazole and cambendazole), i.e. it can cause malformations in the embryos and therefore should not be administered to pregnant animals. Albendazole is massively used in ruminants, less in swine, poultry, horses and pets. It is not used in agriculture.
Levamisole is the most veteran anthelmintic in this combination. It was introduced by JANSSEN already in the 1960s (NILVERM, RIPERCOL). It has a broad-spectrum of activity against roundworms (gastrointestinal and pulmonary) but no efficacy whatsoever against tapeworms and flukes. It is also completely ineffective against external parasites of livestock (ticks, flies, lice, mites, etc). Levamisole has been used massively worldwide in countless generic formulations. It still remains one of the most preferred low-cost anthelmintics for livestock worldwide. It is only marginally used in horses and pets. It is not used in agriculture.
Albendazole and levamisole administered as a drench have no residual effect, i.e. they kill the parasites shortly after administration, but do not significantly protect the animals against re-infestation by infective stages in their environment. Whether such protection can be ensured by abamectin depends on the resistance status of the concerned worm species.
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.
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.
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