WHICH WORMER FOR WHAT
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.
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
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
Valbazen SC 2.5%PfizerAlbendazoleRoundworm, lungworm, flukeOral drenchCo.Se8 days
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
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