Worming in Horses: Modern Approaches Explained

Worm control is an essential part of keeping horses healthy, but advice around worming has changed significantly in recent years. The traditional approach of routine, blanket worming is no longer recommended, as it can contribute to anthelmintic resistance and may not effectively protect your horse.

A modern worming programme is targeted, evidence-based, and tailored to the individual horse.

Why Has Worming Advice Changed?

Over time, parasites have developed resistance to many commonly used wormers. This means some treatments are becoming less effective, putting horses at greater risk.

Modern worming aims to:

• Reduce parasite burdens effectively

• Slow the development of resistance

• Avoid unnecessary medication

• Protect long-term equine health

Common Parasites in Horses

The most significant parasites affecting horses in the UK include:

• Small redworms (cyathostomins)

• Large redworms (strongyles)

• Tapeworms

• Roundworms (primarily in young horses)

Different parasites pose risks at different times of year, which is why a tailored approach is important.

Faecal Egg Counts (FECs)

What Is a Faecal Egg Count?

A faecal egg count (FEC) is a laboratory test that measures the number of parasite eggs present in your horse’s droppings.

Why Are FECs Important?

• Identify whether worming treatment is necessary

• Reduce unnecessary use of wormers

• Help monitor parasite control on your yard

• Support targeted, responsible treatment

Most adult horses require FECs every 8–12 weeks, depending on risk and management.

Targeted Worming

Under a modern approach:

• Only horses with significant egg counts are treated

• The correct wormer is selected based on the parasite identified

• Treatment is timed appropriately

This reduces resistance and keeps wormers effective for the future.

Tapeworm Control

Tapeworms are not reliably detected by standard FECs.

Control may involve:

• A blood or saliva test

• Targeted treatment once or twice a year, depending on risk

Your vet can advise on the most appropriate approach.

Young, Elderly, and High-Risk Horses

Some horses require additional monitoring:

• Foals and young horses are more susceptible to roundworms

• Older horses may have reduced immunity

• Horses with poor body condition or underlying illness

These horses may need a modified worming plan.

Pasture Management Matters

Good pasture management is a vital part of parasite control:

• Regular poo-picking

• Avoiding overstocking

• Rotational grazing

• Mixed grazing where possible

Worming alone is not enough without good management.

When Should You Speak to Your Vet?

You should contact your vet if:

• Your horse is losing weight or condition

• FEC results are consistently high

• You are unsure which wormer to use

• You are managing multiple horses or a shared yard

A tailored plan ensures effective, responsible parasite control.