To worming products
What exactly is resistance?
Resistance is when a greater frequency of individuals in a parasite population,
usually affected by a dose or concentration of compound, are no longer affected.
Once resistance is present in a worm population, the health, welfare and
performance of horses infested with resistant worms will be compromised.
For this reason it is essential that your horse is dosed accurately according
Using too low a dose of wormer may speed up the development of resistance.
On the other hand, frequent, unnecessary worming may also increase the
potential for development of resistance. The key to reducing the likelihood
of resistance is choosing the right wormer, then giving it at the correct
dose and time. Worm egg counts have an important role in this, as they
help you to identify when your horse actually needs to be wormed.
Use worm egg counts as part of a SMART worming programme.
Resistance to other actives
- • Benzimadazole (BZ) resistance recognised in Kentucky in 1965 and first reported in UK in 1974.
It is now widespread in the UK.
- • Surveys have shown that where BZ resistance has been confirmed, continued use of this chemical group of wormers resulted in an increased level of resistance
- • Even after a prolonged break from a certain group of wormers, worms remain resistant to that group and this cannot be reversed
- • Resistant strains are easily spread by horses grazing together and this is more likely in groups of more than 6 horses