Seasonal Parasite Control Autumn

Autumn horse

Autumn is traditionally known as ‘tapeworm time’ as this was a good point in the year to worm hunting horses coming in from a summer at grass. It can be a useful way to remember to target tapeworm but there’s no reason to stick to this routine if another serves you better – and certainly no point in giving a wormer for the sake of it without knowing if there are parasites present to treat and if so, which ones?

The worms we specifically need to be aware of in our horses through autumn and winter are adult redworm, encysted redworm, tapeworm and bots. What to do when will depend a little on your management routine and personal choice along with the risk factor of your horse. Young, old and rescue horses will need more consideration at this time of year than healthy adult horses.

Test first

After a warm and wet summer through which we’ve seen a higher number of positive worm counts than normal across the UK (probably due to perfect conditions for the redworm lifecycle) it’s important to keep a close eye on red worm and ascarid activity with a worm egg count for each horse.

Tapeworm should be targeted twice a year, every six months with an EquiSal Tapeworm test to determine whether your horse is one of the minority (fewer than 29%) of infected horses requiring treatment. Whether you test now in conjunction with your autumn worm egg count or before to your winter encysted redworm treatment depends on your schedule and preferred treatment choices.

The results of the tests will inform the treatment choices open to you and your prescriber.



Horse Worm Treatment Prescribing Options

If treatment for just tapeworm is indicated then a praziquantel only wormer would be one of the preferred choices, now available only through your vet. Alternatively, a double dose of pyrantel can be recommended for administration if;

  • ascarids are also present (more likely in foals or youngstock)
  • the redworm population in question is known to not be resistant to pyrantel.

Where treatment for redworm is indicated at the same time as tapeworm treatment, then an ivermectin + praziquantel combination wormer would be the recommended selection through Spring, Summer and Autumn.

In winter when a proactive treatment for the possibility of encysted redworm is advised (an ELISA blood test for encysted redworm is now available through your vet for low risk horses) then a moxidectin + praziquantel would be preferred treatment or alternatively a praziquantel only wormer followed two weeks later by a moxidectin only wormer or 5-day fenbendazole where there is no resistance known.


Bots are not worms but the maggot stage of a large fly which is active during the summer months. It lays eggs on the hairs of the horse’s coat that appear like tiny cream or yellow flecks. These eggs are ingested by the horse as it scratches and hatch in the mouth, slowly migrating to the stomach where they can cause mild irritation. Treat with ivermectin or moxidectin after the first frost has killed off fly activity. You could combine this with your encysted redworm dose.

What to do now

This autumn plan a worm count for redworm and roundworm, EquiSal test for tapeworm and keep an eye out for bots and pinworm activity. This will help you to decide which wormer to treat with for your winter dose. As responsible horse owners our job is to keep parasite levels in check so that our horses remain healthy and to use the drugs we have responsibly to minimise the build-up of resistance to worming chemicals.

This means being aware of which parasites to target seasonally or in specific conditions so there are often a few considerations to take into account. If in doubt please call our friendly helpline to speak to one of our qualified advisors or chat to your prescriber to plan a best course of action.

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