Spring & Summer Equine Worming

27th May 2020

One of the many jobs of the horse owner is assessing your horses worming needs for the year ahead. Some things to bear in mind as you decide on your horses’ needs are:

  • • No one single treatment will fit all horses
  • • Checking worm burden prior to worming can have certain advantages, depending on your farm situation
  • • Pasture Management has a direct effect on worm burden
  • • Roundworms and tapeworms need to be treated very differently
  • • Young stock and veterans need to be wormed more regularly
  • • Any new horses arriving at your yard should be wormed

Spring is an important time for horse worm control as the breeding cycle is dormant during the cold winter months. The increase in temperature in the spring leads to recrudescence of larvae and recommencement of the worms breeding cycle.

The most holistic method of approach to annual worming is to include a Faecal Worm Egg Count prior to de-worming in spring (ideally spring and autumn). A Faecal Egg Count (FWEC) is a method of determining how many internal parasite eggs are present in a particular dung sample. It may also be possible to determine the different types of worms or other parasites present. It should be used as a guide, rather than an exact science as other factors like stress can influence how may parasite eggs are shed in the dung.

The Akker Worm Egg Count Kit (FWEC) is available to purchase from Farm & Stable Supplies https://www.farmstable.com/equisal-tapeworm-count-kit.html

Internal parasites found in horses include:

  • • Small strongyles (small redworm)
  • • Large strongyles (large redworm)
  • • Tapeworms
  • • Roundworms
  • • Pinworm
  • • Encysted small redworm
  • • Lungworm

A convenient time to treat tapeworm is in spring and autumn – a blood test is available to monitor antibodies to tapeworms. There’s also a commercially available test for tapeworm burden, using a sample of your horses’ saliva - the Equisal Tapeworm Saliva Testing Kit.
Both of these tests measure antibodies, so high test results may also show in horses that have been exposed to the disease from up to three months. Tapeworm can also be transferred in infected forage, which can mean it gets imported with forage.

Not all wormers are effective against all types of worms, so if your horse does need worming, make sure the brand of wormer you choose contains the correct active ingredients for the worms you are looking to treat.

Active Ingredients

Moxidectin: is effective against encysted developing small redworm larvae as well as large redworm, pinworms, intestinal threadworms, ascarids (adult and larval stages). It will also treat bots. Moxidectin should be used only in mid-winter where possible. This can help prevent resistance to this drug on small redworm.


lvermectin-based wormers are effective against both larval and adult stages of small redworms as well as pinworms, intestinal threadworms, stomach worms, lungworms, neck threadworms, ascarids neck threadworm, lungworm and bots.


This is effective against most adult roundworms and needs to be administered at twice the standard dose when being used for the treatment of tapeworm.


Effective against all three known species of equine tapeworm in a single dose. It is not effective against other worm types.


A five-day course of a fenbendazole-based wormer can be given mid-winter for treatment of small redworm encysted larvae. Fenbendazole as a single dose is a very good selective drug for incorporation into stud farm programmes.


This is the term used when a number of parasites survive a normally lethal dose of treatment. This varies between parasites. The term should not be used as a generalisation, certain parasites show hardly any sign of resistance, even after many years of use, whereas others can have a reduction of efficacy up to 20% or so.

Careful choice of an annual worming programme, to suit your situation and stock, in conjunction with your veterinary surgeon, should be evaluated each year. This should be done to ensure your horses are managed effectively with resistance avoided and monitored. Contact our sales office for more information on this service.

Support during Worming

Gut motility can become imbalanced during a worming treatment, causing the gut to become inflamed. It is always a great idea to use an Equine Probiotic supplement such as Synbiovit or Diazorb for cases of diarrhoea at the time of worming to promote healthy gut bacteria.

For more assistance on which wormer to choose, please do call the team, we have a number of SQP team members who would be happy to help advise you.

Email us at mail@farmstable.com

or call the team directly on 01730 815 800