12 April 1996


Most wormers are broad-spectrum, with an ever increasing range of activity against the major internal parasites. We detail the products available and the parasites they control

ANTHELMINTICS are generally closely related by their chemical structures and modes of action.

Three broad-spectrum groups are recognised – the avermectins (group 1), the benzimidazoles (white drenches) (group 2) and the levamisoles and morantel (group 3).

Anthelmintics belonging to these groups, will have activity against most, if not all, species of roundworms (gut and lung). Some will also tackle liver fluke. Endectocide compounds (avermectins) in group 1 are also active against ectoparasites.

Other anthelmintics available are more specific in the parasites they kill and are referred to as narrow-spectrum drugs. Most in this category are active against liver fluke, some also against certain ectoparasite species. The range of activity of an anthelmintic product can be further increased by formulating a narrow-spectrum flukicide with a broad-spectrum anthelmintic. Such combinations constitute the so-called "fluke-and-worm" drenches.


AT the makers recommended dose rates, the benzimidazoles, levamisole and ivermectin are all highly effective against the adult and developing larval stages of the gastro-intestinal nematodes parasitic in sheep.

There is little to choose between any of them when selecting an anthelmintic for the treatment of susceptible populations of worms which cause parasitic gastro-enteritis in lambs during the summer. However, the possible presence of resistant nematodes should be considered when choosing an effective anthelmintic.

In general, the benzimidazoles, levamisole and ivermectin also possess high activity against the adult and immature larvae of Nematodirus battus, though the activity of some of the earlier benzimidazoles against developing larvae can be variable.

Temporarily non-active (arrested) fourth-stage larvae of the abomasal nematodes of sheep are susceptible to a wider range of anthelmintics than are those of cattle. Fenbendazole, oxfendazole, albendazole, levamisole and ivermectin are all effective against arrested fourth-stage larvae and can, therefore, be used in the treatment and control of winter scours in sheep. The use of anthelmintics which lack activity against arrested larvae may result in the need for repeated treatment.

Outbreaks of coughing may be seen during the autumn months associated with infection by the lungworm Dictyocaulus filaria. Fenbendazole, oxfendazole, albendazole, mebendazole, febantel, levamisole and ivermectin are all highly effective against the adult and fourth-stage larvae of this parasite.

The activities of the earlier benzimidazoles against D filaria can be variable and it is recommended that the dose rates of thiabendazole and thiophanate be increased if they are to be used in the treatment of lungworm infections.

Tapeworm infections

Despite their size and the fact that segments can often be seen in the faeces of infected animals, there is little convincing evidence that tapeworm infections have an adverse effect on performance. The benzimidazoles, fenbendazole, oxfendazole, albendazole, mebendazole and febantel are all effective in controlling tapeworm infections.


Oxyclozanide, nitroxynil, closantel, triclabendazole and albendazole (at an increased dose rate), are all highly effective against adult flukes present in the bile ducts and are therefore suitable for the treatment of chronic fascioliasis in late winter and spring.

Disease seen during the autumn and winter months is commonly associated with mixed infections of adult and immature flukes and is best treated with triclabendazole, closantel or nitroxynil because of their higher activities against immature flukes.

Combined treatment of gastro-intestinal nematodes and liver flukes

A number of products are marketed for the combined treatment of gastro-intestinal nematodes and liver fluke in sheep.

With the exception of albendazole, which has to be used at increased dose rates for this purpose, all the products contain a mixture of two chemicals, one active against liver fluke the other active against gastro-intestinal nematodes.

Combinations available include oxfendazole/oxyclozanide, levamisole/oxyclosanide, mebendazole/closantel and levamisole/ triclabendazole.

Where sheep are to be treated during autumn and winter, particularly at tupping time or on housing, it is desirable that the anthelmintics should have activity not only against adult gastro-intestinal nematodes and liver fluke, but also against arrested fourth-stage larvae and immature fluke.

SHEEP WORMER GUIDE Group 1: Avermectins




IvomecMSD AgvetIvermectinRoundworm, lungwormInjectionNone42 days

OramecMSD AgvetIvermectinRoundworm, lungwormOral drenchNone14 days

Panomec*MSD AgvetIvermectinRoundworm, lungwormInjection None42 days

*POM – prescription only medicine


Witholding periods must be checked against

current recommendations. For milking cattle and sheep, check that the

product can be used and check the milk witholding time BEFORE administration. Avermectins, levamisole, and bolus preparations are generally not recommended for milking animals.

Information only correct

to Dec 95.

Group 2: Benzimidazoles




Allverm 4%CrownRicobendazoleRoundworm, lungworm, flukeOral drenchSe.Co10 days

Bayverm ArmadoseBayerFebantelRoundworm, lungwormOral drenchNone14 days

Bayverm 1.9%BayerFebantelRoundworm, lungwormIn-feedNone14 days Pellets

Bayverm 2.5%BayerFebantelRoundworm, lungwormOral drenchNone14 days

Bayverm 2.5% SCBayerFebantelRoundworm, lungwormOral drenchCo.Se14 days

Bental SC 2.265%C-VetRicobendazoleRoundworm, lungworm, flukeOral drenchCo.Se10 days

Bovex 2.265%ChanelleOxfendazoleRoundworm, lungwormOral drenchNone21 days

FasinexCibaTriclabendazoleFlukeOral drenchNone28 days

Fendazole 2.5%Bimeda UKFenbendazoleRoundworm, lungwormOral drenchNone21 days

HapadexScheringNetobiminRoundworm, lungworm, flukeOral drenchNone5 days Plough

MolaminDallas KeithThiophanateRoundwormMolasses7 days mineral lick

Nemafax 14Rhone-ThiophanateRoundwormIn-feedNone7 days Merieux

Ovitelmi S & CJanssenMenbenzadoleRoundworm, lungwormOral drenchCo.Se7 days

OxfenilVirbacOxfendazoleRoundworm, lungwormOral drenchNone21 days

Panacur 1.5%HoechstFenbendazoleRoundworm, lungwormIn-feedNone14 days

Panacur SC 2.5%HoechstFenbendazoleRoundworm, lungwormOral drenchCo.Se14 daysPanacur SC 5%HoechstFenbendazoleRoundworm, lungwormOral drenchCo.Se14 days

Panacur SC 10%HoechstFenbendazoleRoundworm, lungwormOral drenchCo.Se14 days

Panacur 2.5% &HoechstFenbendazoleRoundworm, lungwormOral drenchNone14 days

Panacur 5%HoechstFenbendazoleRoundworm, lungwormOral drenchNone14 days

Parafend NorbrookOxfendazoleRoundworm, lungwormOral drenchNone14 daysParafend LVNorbrookOxfendazoleRoundworm, lungwormOral drenchNone14 days

Proftril PfizerAlbendazoleRoundwormBolusNone100 days

Provit blocDallas KeithThiophanateRoundwormCerealNone7 days

feed block

Rycoben 2.5%YoungsRicobendazoleRoundworm, lungworm, flukeOral drenchNone10 daysAnimalHealth

Supaverm JanssenMenbendazoleRoundworm, lungworm, flukeOral drenchNone28 daysClosantel

Systamex SCMallinckrodtOxfendazoleRoundworm, lungwormOral drenchCo.Se21 days

Systamex 2.265MallinckrodtOxfendazoleRoundworm, lungwormOral drenchNone21 daysSystamex 906MallinckrodtOxfendazoleRoundworm, lungwormOral drenchNone21 days

Systamex MallinckrodtOxfendazoleRoundworm, lungworm, flukeOral drenchCo.Se21 days Fluke SCOxyclozanide

Synanthic Sel/CoMallinckrodtOxfendazoleRoundworm, lungwormOral drenchCo.Se21 days

Thibenzole-MSD Agvet ThiabenzoleRoundworm, lungwormOral drenchNone28 days

Valbazen lamb dosePfizerAlbendazoleRoundworm, lungworm, flukeOral drenchCo.Se8 days

Valbazen 2.5%PfizerAlbendazoleRoundworm, lungworm, flukeOral drenchNone8 days

Total Spectrum

Valbazen SC 2.5%PfizerAlbendazoleRoundworm, lungworm, flukeOral drenchCo.Se8 days

Total Spectrum

Valbazen SC 2.5%PfizerAlbendazoleRoundworm, lungworm, flukeOral drenchCo.Se8 days

Total SpectrumVit A

Hidose PlusD3 E

Wormalic Dallas KeithThiophanateRoundworm, lungworm,MolassesNone7 daysliquid feed

Wormaway FenbenDeosanFenbendazoleRoundworm, lungwormOral drenchNone21 days

Zerofen 2.5%ChanelleFenbendazoleRoundworm, lungwormOral drenchNone21 days

Zerofen 5% &ChanelleFenbendazoleRoundworm, lungwormOral drenchNone21 days

Zerofen 10%ChanelleFenbendazoleRoundworm, lungwormOral drenchNone21 days

Group 3: Levamizoles/Morantel




Armadose BayerLevamisoleRoundworm, lungwormOral drenchNone28 days

BionemMallinckrodtLevamisoleRoundworm, lungwormOral drenchNone21 days

Chanaverm 1.5%ChanelleLevamisoleRoundworm, lungwormOral drenchNone21 daysChanaverm 7.5%ChanelleLevamisoleRoundworm, lungwormOral drenchNone21 days

Combinex CibaLevamisoleRoundworm, lungworm, flukeOral drenchNone28 daysTriclabendazole

Decazole Bimeda UKLevamisoleRoundworm, lungwormOral drenchNone28 daysDecazole ForteBimeda UKLevamizoleRoundworm, lungwormOral drenchNone28 days

Klomisole Bimeda UK LevamisoleRoundworm, lungworm, flukeOral drenchNone28 daysOxyclozanide

Levacide NorbrookLevamisoleRoundworm, lungwormInjectionNone21 days

Levacide 1.5%NorbrookLevamisoleRoundworm, lungwormOral drenchNone21 days

Levacide 3%NorbrookLevamisoleRoundworm, lungwormOral drenchNone21 days

Levacide low

volume 7.5%NorbrookLevamisoleRoundworm, lungwormOral drenchNone21 days

Levacur SCHoechstLevamisoleRoundworm, lungwormOral drenchCo.Se21 days

Levadin 15UnivetLevamisoleRoundworm, lungwormOral drenchNone21 days

Levadin 75UnivetLevamisoleRoundworm, lungwormInjection None28 days

LevafasNorbrookLevamisoleRoundworm, lungworm, flukeOral drenchNone28 days


Levafas DiamondNorbrookLevamisoleRoundworm, lungworm, flukeOral drenchNone28 days


Nilzan GoldMallinckrodtLevamisoleRoundworm, lungworm, flukeOral drenchNone28 days

Nilzan SuperMallinckrodt-LevamisoleRoundworm, lungworm, flukeOral drenchCo.Se28 daysOxyclozanide

Nilverm GoldMallinckrodtLevamisoleRoundworm, lungwormOral drenchNone21 days

Nilverm SuperMallinckrodtLevamisoleRoundworm, lungwormOral drenchCo.Se21 days

Ripercol 3.2%JanssenLevamisoleRoundworm, lungwormOral drenchNone35 days

SilbanC-VetLevamisoleRoundworm, lungwormOral drenchNone21 days

SureYoungsLevamisoleRoundworm, lungwormOral drenchNone21 days

Vermaject Bimeda UK LevamisoleRoundworm, lungwormInjection None28 days

Vermisole DrenchBimeda UK LevamisoleRoundworm, lungwormOral drenchNone28 daysVermisole ForteBimeda UKLevamisoleRoundworm, lungwormOral drenchNone28 days

Vermisole Bimeda UK LevamisoleRoundworm, lungwormInjection None28 days

VermofasBimeda UK LevamisoleRoundworm, lungworm, flukeOral drenchNone28 daysOxyclozanide

Wormaway DeosanLevamisoleRoundworm, lungwormOral drenchNone28 days



Wormaway DeosanLevamisoleRoundworm, lungwormInjection None28 days


ExhelmPfizerMorantelRoundwormOral drenchNone3 days

Group 4: Other




FlukiverJanssenClosantelRoundworm, flukeOral drenchNone28 days

Trodax 34%Rhone-MerieuxNitroxynilFluke, roundwormInjectionNone60 days

ZanilMallinckrodtOxyclozanideFlukeOral drenchNone28 days