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Wormer Classes for Cattle and Sheep - Yellow Wormers

Last week, we learned about white wormers, the first wormer class. This week, levamisoles - or yellow wormers - are on the agenda.

So what are the important points of note on these products?

  • There is only one ingredient in the levamisole family, unlike the other classes.
  • Levamisole works by causing parasites to become paralysed.
  • Levamisole should never be used on dairy cows, even during the dry period. This includes dairy heifers.
  • Once sold in all three formats, the pour-on and injectable versions of levamisole are no longer available. The product is now marketed as an oral drench.
  • Both 1.5% and 7.5% concentrations are available on the market. Not the 1.5% will have a large dose for bigger animals so ensure your dosing gun is suitable.
  • Levamisole is commonly marketed in combination worm and fluke products, such as Chan Broad Spec.
  • The safety index for levamisoles is not as high as, for example benzimidazoles. What does this mean? Basically, the amount or dosage needed to bring about toxicity is lower. Be careful when using the product that you adhere to the recommended rates. NEVER under dose animals however. Pick the heaviest animal in a given contemporary group and dose all at this rate. If there is a large weight range in the group, split the group into heavy and light animals and use two dose rates.
  • Withdrawal periods (meat) are quite workable with levamisole products (18 days for e.g. Chanaverm Plus). Note, when in combination with a flukicide this may increase.
Practical use
  • Sheep farm - use levamisole as a second or third dose as necessary. A white wormer will likely have been used as the first treatment against Nematodirus and rotation of classes for subsequent treatments is best practice.
  • Cattle farm - use levamisole during the grazing season when animals require a dose. The product is useful where lungworm is suspected as the process of expelling dead worms post-treatment is less severe with levamisole than e.g. a clear wormer so there are less likely to be complications.
  • Cattle farm - where pour-ons are planned at housing time (due to their effecacy against both internal and external parasites like lice and mites) use levamisole at grass when needed. Rotating of wormers is best practice. Levamisole should be avoided as a housing treatment as it is not effective against inhibited stomach worm larvae and these can cause problems later in the winter (Winter Scour Syndrome).
Keep Learning

Yellow wormer

Yellow wormer with flukicide

White wormers

Last week, we learned about white wormers, the first wormer class. This week, levamisoles - or yellow wormers - are on the agenda.

So what are the important points of note on these products?

  • There is only one ingredient in the levamisole family, unlike the other classes.
  • Levamisole works by causing parasites to become paralysed.
  • Levamisole should never be used on dairy cows, even during the dry period. This includes dairy heifers.
  • Once sold in all three formats, the pour-on and injectable versions of levamisole are no longer available. The product is now marketed as an oral drench.
  • Both 7.5% and 1.5% concentrations are available on the market. Not the 1.5% will have a large dose for bigger animals so ensure your dosing gun is suitable.
  • Levamisole is commonly marketed in combination worm and fluke products.
  • The safety index for levamisoles is not as high as, for example benzimidazoles. What does this mean? Basically, the amount or dosage needed to bring about toxicity is lower. Be careful when using the product that you adhere to the recommended rates. NEVER under dose animals however. Pick the heaviest animal in a given contemporary group and dose all at this rate. If there is a large weight range in the group, split the group into heavy and light animals and use two dose rates.
  • Withdrawal periods (meat) are quite workable with levamisole products (20 days for e.g. Chanaverm 7.5%).
Practical use
  • Sheep farm - use levamisole as a second or third dose as necessary. A white wormer will likely have been used as the first treatment against Nematodirus and rotation of classes for subsequent treatments is best practice.
  • Cattle farm - use levamisole during the grazing season when animals require a dose. The product is useful where lungworm is suspected as the process of expelling dead worms post-treatment is less severe with levamisole than e.g. a clear wormer so there are less likely to be complications.
  • Cattle farm - where pour-ons are planned at housing time (due to their effecacy against both internal and external parasites like lice and mites) use levamisole at grass when needed. Rotating of wormers is best practice. Levamisole should be avoided as a housing treatment as it is not effective against inhibited stomach worm larvae and these can cause problems later in the winter (Winter Scour Syndrome).
Keep Learning

Chanaverm 7.5%

White wormers

12
Jun