Guide · Ireland

Horse worming in Ireland: the vet's prescription, egg counts and a mild winter

Last reviewed 6 November 2026

For years an Irish horse could be wormed on the strength of a trip to the co-op. Since 1 December 2025 every wormer has needed a vet's prescription, and before a vet can write one for routine worming, the law asks what the horse has had for the last year and what its egg counts showed. The prescription is the new part. The questions behind it are the ones good worming advice was already asking.

This is a summary of published rules and guidance, not veterinary advice. A worming programme is something to set with your vet, who now has to be involved anyway. Products and labels change; read the current label before you dose.

In the UK, the US, Australia or Canada? Read the UK worming guide, the US deworming guide, the Australian one or the Canadian one instead. In Great Britain a qualified retailer can still supply a horse wormer without a vet.

What changed on 1 December 2025

EU law makes medicines for food-producing animals prescription-only, and in law a horse is a food-producing animal, whatever its owner intends. The Veterinary Medicines Regulation applied from January 2022, and antiparasitic products were relabelled as prescription medicines that year, but the Department of Agriculture deferred the requirement for them several times so that farmers and merchants could adjust. In July 2025 the Minister announced what he called a further and definitive extension, to 1 December 2025. Since that day every wormer for gut, stomach and lung worms, fluke and lice remedies, and fly and mite treatments for cattle, sheep and horses has needed a prescription.

Two things people hope are exceptions are not:

A horse signed out of the food chain. The Department's prescribing guidance carves out only the case where the vet gives a non-antimicrobial medicine to such a horse personally. A wormer that you buy and give yourself still has to be prescribed through the system.
Buying from abroad. The Veterinary Medicinal Products Act 2023 forbids buying a prescription veterinary medicine at a distance from a seller in another EU country or outside the EU. A tube ordered from a British website is not a way round the rule.

How the prescription works

The vet writes it on the National Veterinary Prescription System, and you receive its number by text. You take that number to any registered dispenser: your vet, a pharmacy, or a licensed merchant or co-op, including a licensed Irish online retailer. Under the Veterinary Medicinal Products Regulations 2024 a prescription for a wormer is valid for six months from the day it is issued. It can be dispensed in parts, some now and the rest later, as long as all of it is dispensed within those six months. An antimicrobial prescription, by contrast, lasts five days.

Only a vet can prescribe. Pharmacists and the licensed merchants' responsible persons can still sell a wormer, and advise on it, but only against a vet's prescription.

What the vet has to ask first

For routine worming, the treatment a horse gets because it is due rather than because it is ill, the 2024 regulations require the vet to complete a written proper assessment protocol before prescribing. You can supply the information yourself. The protocol asks, at least, for:

the horses: age, sex, weight, breed, and confirmation that none is showing signs of disease;
the land: its size, soil, stocking rate and how it is grazed;
every antiparasitic used on the holding in the previous twelve months, and any diagnostic evidence, such as a faecal egg count or an egg count reduction test;
any evidence of resistance on the farm;
the treatments for the targeted parasite over the last three years, and its clinical history;
the husbandry that slows resistance: dung removal, grazing patterns, biosecurity.

The vet keeps the protocol for five years and gives you a copy. It is not needed where the vet already provides ongoing services to the yard, including clinical contact with the horses. An egg count is not compulsory, but it is the first piece of evidence the protocol names, and a vet looking at a horse's three-year history will want to see one.

How often: what Irish advice says

The Irish Equine Centre summarised the current recommendations in a 2025 report to Horse Sport Ireland. For a mature horse they take two tiers: a baseline, then extra doses only for the horses whose counts show they need them.

Horse	Treatments
Mature horse (about 5 to 15)	a baseline of one or two strongyle treatments a year; a tapeworm treatment once a year if a saliva or blood test shows one is needed; one or two more only for a high shedder on its egg counts
Three- and four-year-olds	three or four a year, with a tapeworm treatment at least once in the second half of the year
Foals	roundworm (ascarids) at 2 to 3 months and again at about 5 months; the first egg count at 5 to 6 months; the first strongyle and tapeworm treatment between 6 and 9 months

The same report shows why the counts save doses. At a screening at Emerald Equestrian Centre in October 2025, 10 of 12 foals, 7 of 13 mares and 13 of 16 three- and four-year-olds had no eggs at all. None of the mares was a high shedder; two of the young horses were, at 1,000 and 1,300 eggs per gram. Three of ten mares tested by saliva carried enough tapeworm to treat, and the other seven did not. The sample was small, but the pattern is the familiar one: most horses need little, and a few need a lot.

Small redworm, and a winter that does not stop it

In May 2025 the Irish Equine Centre warned of a spike in positive small redworm tests. Small redworm is extremely common, increasingly resistant to every wormer available, particularly fenbendazole and pyrantel, with resistance emerging to the macrocyclic lactones, and its larvae can lie encysted in the gut wall for months. The advice it published draws three conclusions:

Test while the horses graze. Egg counts every eight to twelve weeks during the grazing season, and late-winter testing for horses that graze all year round, which in Ireland's mild, wet winters is a lot of them.
The winter dose is no longer automatic. Every horse used to get a larvicidal treatment against encysted larvae in late autumn or winter; that now follows a risk assessment, because doing it to every horse breeds resistance. A blood test can show a horse carries a low burden and can skip it, provided it is taken at least four months after the last wormer.
The paddock does much of the work. Remove droppings fully at least twice a week, keep to at least one acre per horse, and rest paddocks for six months or graze them with sheep or cattle, minding the liver fluke risk that mixed grazing brings.

The records the law now asks for

Because a horse is a food-producing animal, its owner or keeper has to keep a record of every medicine it is given, prescription or not: what it was, when, who gave it and when the withdrawal period ends, along with the disposal of anything unused. The 2024 regulations set the keeping period, with copies of the prescriptions, at at least five years. That is also, more or less, the history the next prescription will ask for.

In Northern Ireland

The prescription rule stops at the border. Northern Ireland still supplies wormers as Great Britain does: a vet, a pharmacist or a registered animal medicine adviser, an SQP, can supply the medicines classed POM-VPS, the category horse wormers are mostly sold under in the UK, without a vet's prescription. What changed there on 1 January 2026 is where they come from: the EU's rules on distributing veterinary medicines now apply in full under the Windsor Framework, and retailers based in Great Britain can no longer supply veterinary medicines to Northern Ireland, so a British website is not a source there either. The advice above on egg counts and small redworm holds on both sides of the border.

Why the plan drifts

A count-based programme is a list of dates and numbers: when each horse was last counted, what it shed, what it was given, and whether the next count fell. Until December 2025 an Irish owner who lost track could buy another tube and carry on. Now the gap shows up at the vet's, as a protocol with nothing to put in it, and the cheapest prescription to write is the one backed by a year of counts already on record.

Questions people ask

Do I need a prescription to buy a horse wormer in Ireland?

Yes. Since 1 December 2025 every antiparasitic medicine for horses, cattle and sheep has been prescription-only, and the prescription has to come from a vet, through the National Veterinary Prescription System. Merchants, co-ops, pharmacies and vets still sell wormers, but only against one. A horse signed out of the food chain is no exception: a wormer you give it yourself still needs a prescription.

How long is a wormer prescription valid in Ireland?

Six months from the day it is issued, under the Veterinary Medicinal Products Regulations 2024. It can be dispensed in parts, buying some of the wormers now and the rest later, but everything on it has to be dispensed within those six months.

Does the vet have to see my horse before prescribing a wormer?

Not necessarily. For routine worming the vet completes a written assessment, the proper assessment protocol, and you can supply the information for it: the horses, the land and how it is grazed, every wormer used in the last twelve months, any egg counts, and the treatments for the targeted worm over the last three years. The protocol is not needed where the vet already provides ongoing care to the yard, including contact with the horses. You get a copy.

Can I buy horse wormers online from the UK?

No. Irish law forbids buying a prescription veterinary medicine at a distance from a seller in another EU country or outside the EU, the UK included. A licensed Irish online retailer can supply a wormer against your NVPS prescription.

Keep the history your vet will ask for

EquiDiary keeps each horse's egg counts, wormers and products in one history. Log the egg count with its result, log the wormer with the product, the dose and the date, and the twelve months a proper assessment protocol asks about are on one page. Put each horse's baseline treatment on a rhythm in the care schedule and a morning email says when it is due. Your vet, your yard manager and you all see the same record.

Start free for 3 months

Sources

Animal Health Ireland — New antiparasitic medicine rules (the products covered, where to buy, dispensing within six months)
DAFM — Minister announces further extension to date for up-regulation of antiparasitics (21 July 2025: 1 December 2025)
S.I. No. 462 of 2024, Veterinary Medicinal Products Regulations 2024: reg. 3 (six months), reg. 5 and the Schedule (the proper assessment protocol), reg. 19 (keepers' records, five years)
Veterinary Medicinal Products, Medicated Feed and Fertilisers Regulation Act 2023, s. 24 (buying at a distance from another country)
DAFM — National Veterinary Prescription System: frequently asked questions (Q29, horses out of the food chain; antimicrobials five days) and NVPS — How to prescribe: equine
HPRA — Antiparasitic veterinary medicinal products (why no derogation; the deferrals)
Northern Ireland: GOV.UK — the government's approach to veterinary medicines in Northern Ireland (in full from 1 January 2026), wholesaler and retailer supply from 2026, VMD — information for retailers, pharmacists and SQPs and Department of Health — legislation covering veterinary medicines (what an SQP may supply)
Irish Equine Centre — Faecal worm egg count and saliva test screening: report to Horse Sport Ireland (October 2025)
Irish Equine Centre issues warning over small redworm (The Irish Field, 16 May 2025, with Prof. Jacqui Matthews)

Rules and guidance are revised; check the current version before relying on any detail here, and confirm the programme with your vet.

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Next: horse passports in Ireland — the premises number, the microchip and the six-month deadline.