Tapeworm in horses

Tapeworms in horses are the largest worms to affect horses in the UK. Three species of tapeworms are known to infect the horse in the UK : Anoplocephala perfoliata is the most common one and can grow up to 8cm long and 1.5m wide.  Tapeworms are short, white, and flat in appearance.

How do horses get tapeworm?
They use an intermediate host as part of their lifecycle.  This intermediate host is the ‘pasture mite’ which is readily found on grass, and can also be found in hay and straw. The pasture mite ingests the tapeworm eggs on the ground and then the mites infest the horse. The eggs develop over a few months in the mite.

What do tapeworms do to horses?
Tapeworms live in the horse’s intestinal tract and many horses tolerate them well. This is why it can be tricky to know if a horse has a tapeworm burden, as there aren’t always obvious signs. Tapeworms draw nutrients away from the horse and can cause severe damage to the horse’s intestinal tract. In large numbers tapeworm can cause loss of condition and an obstruction which can lead to increased risk of intestinal issues, impactions and spasmodic colic.

Tapeworms infect horse of all ages. Young horses who contact tapeworm infection are at more risk of developing ileocecal colic.

Why do I need to do a tapeworm saliva test?
Only 27% of horses actually need treating for tapeworm.  Tapeworms won’t show up in a standard faecal worm egg count.  This is because the tapeworm eggs are contained within the body segments of the tapeworm, which intermittently break off to be passed out in droppings.  It is sometimes possible to pick up some tapeworm eggs on a faecal egg count but because of the intermittent shedding and containment in body segments, absence of eggs seen does not rule out tapeworm infection.  Therefore, even if your horse has a negative faecal worm egg count it could still have a tapeworm burden.

What are the signs of tapeworms in horses?
In most cases there will be no signs as many horses tolerate them well. However, if your horse is displaying any of the following signs, investigations for tapeworms may be recommended by your vet:

• Episodes of spasmodic colic
• Reduced performance
• Pain and discomfot
• Increased flatulence
• Pawing
• Trying to lie down
• Lethargy
• Bloating
• Refusal to eat
• Dull coat

Speak to your vet – these are all signs that something is not right with your horse and you should investigate possible causes.

When should I do the tapeworm saliva test?
The test should always be done in Autumn as the colder mornings start.  If you’re on the Station House Vets Worm Egg Count Plans, we’ll be in touch to remind you to collect your test kit as part of your plan. Or you can contact us to organise collection, or we can post it out to you.  Email us on prescriptions@stationhousevets.co.uk to organise.

Read more about tapeworms and how to do the tapeworm saliva test